GRB 120219A 08:39:09.66 51:01:54.2 167.86 37.45 Ursa Major 2012/02/19 14:30:08 Swift None has been reported. "This was an image trigger, so no light curve was evident in the BAT data. Swift slewed immediately to the burst, beginning observations with the XRT 128 seconds after the trigger. A bright, uncatalogued X-ray source was found in the initial data. No source was seen in the corresponding UVOT images. A possible optical counterpart was reported from the TNT telescope in Xinglong, China. Stacking 11 exposures of 300 second duration each, an R ~ 21.5 +/- 0.3 object was marginally detected at the edge of the XRT error circle (GCN 12966). This source was also detected in observations made witht eh 1.23 meter CAHA telescope at Calar Alto Observatory, Spain. The observations, in R and V, we done from 7.1 to 13.2 hours after the burst. A faint source with R ~ 22.8 is reported. The source was also detected in V (GCN 12976). " GRB 120218A 21:19:03.4 -25:27:45.4 22.31 -42.73 Capricornus 2012/02/18 00:49:22 Swift None has been reported. Swift was not able to slew to this burst due to a Sun constraint. The light curve showed multiple peaks and lasted about 30 seconds. The Sun constraint will remain in effect until March 20, and so no XRT or UVOT data will be available for this burst before that time. GRB 120215A 02:00:11.41 08:48:07.9 150.2 -50.39 Pisces 2012/02/15 00:41:15 Swift Optical counterpart seen with B = 20.320 "This burst lasted about 15 seconds. The BAT light curve showed a single peak. Swift slewed immediately to the burt and started observations with the XRT after 106 seconds. A fading, uncatalogued X-ray source was seen. No optical counterpart was detected in the corresponding UVOT images. Observations from the PROMPT telescopes on Cerro Tololo, Chile, report detecting a very faint afterglow. The source was not seen in their initial images, which began 69 seconds after the GRB trigger. However, in stacks of images they do detect an afterglow with I = 19.095 +0.287/-0.228 and B = 20.320 +0.361/-0.274 at T+10.27 min and T+20.88 min, respectively (GCN 12956). No other reports of an afterglow detection have been made." GRB 120213A 20:04:02.52 65:24:33.1 98.45 17.41 Draco 2012/02/13 00:27:19 Swift None has been reported. This burst had a single FRED-shaped pulse and lasted about 40 seconds. Swift slewed immediately to the burst, beginning XRT observations 50 seconds after the BAT trigger. A bright, uncatalogued fading source was found in the initial XRT data. No optical counterpart was seen in the initial UVOT images. No ground-based observers have reported detecting an optical afterglow. GRB 120212A 02:52:25 -18:01:30 201.23 -60.72 Eridanus 2012/02/12 09:11:22 Swift Optical counterpart seen with R = 16.3 "This burst lasted about 8 seconds. It had a single peak. Swift was delayed by 44 minutes before it could slew to the burst because of an Earth-limb constraint. After the constraint was lifted, Swift observed the field with both the UVOT, finding an m = 18.31 object (GCN 12933). An X-ray source was also found. The source was fading and was uncatalogued (GCN 12934). The first detection of the afterglow candidate was reported from the Faulkes Telescope South, which detected the afterglow during a course of observations begun 14 minutes after the BAT trigger. The magnitude of the object was R = 16.3 at T+22 minutes (GCN 12932). Additional observations from the MITSuME telescope in Ks detected the afterglow. The magnitude was Ks = 15.13 +/- 0.19 at T+71,2 min. The source was also detected with the Nordic Optical Telescope (NOT) 10.7 hours after the burst. It had a magnitude of R ~ 20.1 at that time (GCN 12941)." GRB 120211A 05:51:00.85 -24:46:29.2 229.76 -23.68 Lepus 2012/02/11 11:58:28 Swift none has been reported. This burst had a single peak and lasted about 30 seconds. Swift slewed immediately to the burst and began XRT observations after 120 seconds. A fading, uncatalogued X-ray source was found in the initial data. No source was found in the initial UVOT data, with a limiting magnitude near m = 19.6. No afterglow has been reported from ground-based observations. GRB 120202A 13:34:02 22:46:29 10.98 79.41 Coma Berenices 2012/02/02 21:40:17 INTEGRAL 0 This burst lasted about 100 seconds. Followup observations using the Swift/XRT showed a source within the INTEGRAL error circle. Initial observations do not show any fading of the source (GCN 12911). A faint source was found using the William Herschel Telescope (WHT), Gemini and UKIRT that corresponded to the XRT source. The WHT data show the object at r = 25.00 +/- 0.15 at 7.4 hours after the burst, and Gemini has r = 24.84 +/- 0.09 at 16.10 hours after the burst. Thus, there is not evidence for brightening in this object. However, a second object, slightly outside the error circle, that is seen to brighten from r = 24.68 +/- 0.09 (WHT) to r = 24.26 +/- 0.06 (Gemini). The object also brightens in the z filter over this period. It was also detected from the UKIRT with K = 18.35 +/- 0.18 (GCN 12912). These two sources, and the fading of the second, are also seen in data from the GROND multi-band imager (GCN 12913). GRB 120129A 02:01:46 59:16:55 131.82 -2.37 Cassiopeia 2012/01/29 13:55:46 Konus-Wind This burst was long, lasting about 4 seconds, and very intense. It was localized by the IPN using data from Konus-Wind, MESSENGER, AGILE, Fermi and Swift. The source was outside of the coded aperture region of the Swift/BAT and SuperAGILE detectors. GRB 120127A 09:16:34 15:52:51 214.11 39.15 Cancer 2012/01/27 04:21:52 MAXI/GSC This burst was detected by the MAXI/GSC instrument on the ISS. The duration of the burst was 10 seconds. No additional detections have been reported. GRB 120121A 16:37:25.13 -23:57:42.4 355.11 15.29 Ophiuchus 2012/01/21 09:42:19 Swift none has been reported. This burst had a single pulse with a FRED shape. The duration of the burst was about 40 seconds. Swift began observing the field with the XRT 119 seconds after the trigger, but no source was seen in the initial data, nor was any OC seen in the initial UVOT data. Subsequent analysis of the XRT data was able to find a source, however (GCN 12886). GRB 120119A 08:00:06.94 -09:04:53.7 229.09 10.8 Monoceros 2012/01/19 04:04:30 Swift Counterpart detected with g' = 18.8 z = 1.728 "This burst lasted about 50 seconds and had three peaks. Swift slewed immediately to the burst and started observing with the XRT 53 seconds after the trigger. A bright, uncatalogued X-ray source was found. In addition, the UVOT found an optical afterglow candidate with m = 19.57. The OC was also seen in ground-based observations. The 1.3 meter PARITEL on Mt. Hopkins, Arizona started observing about 53 seconds after the trigger. In JHKs imaging the object had magnitudes as follows (GCN 12860): t_mid (m) exp.(s) filt mag m_err 10.3 560 J 14.35 0.02 10.3 560 H 13.10 0.02 10.3 560 Ks 11.95 0.02 In addition, the GROND multi-band imager observed the field, finding the following magnitudes in its seven filters (GCN 12863): g' = 18.8 +- 0.1 mag, r' = 17.7 +- 0.1 mag, i' = 16.8 +- 0.1 mag, z' = 16.2 +- 0.1 mag, J = 15.2 +- 0.1 mag, H = 14.6 +- 0.1 mag and K = 14.0 +- 0.1mag The afterglow was also detected by a number of other observers, including those using the PROMPT telescopes on Cerro Tololo, Chile, who noted that the OC faded for the first 2.3 minutes, then brightened until about 14 minutes after the trigger, after which it returned to fading. They also note that it had red colors, with I-R ~ 1 and R-B ~ 2 (GCN 12864). A spectrum was obtained using the Gemini-South telescope. The spectrum covers from 4000 to 8000 angstrom and shows absorption from Al III (1854, 1862), Fe II (2586, 2600), Mn II (2606) and Mg II (2796, 2803) all at a common redshift of z = 1.728. An additional intervening strong Mg II 2796 absorption system is seen at z = 1.212 (GCN 12865). The redshift is confirmed by spectra taken with the 4 meter Shane telescope at Lick Observatory, California (GCN 12866) and the MMT 6.5 meter telescope on Mount Hopkins, Arizona (GCN 12867). " GRB 120118B 08:19:29.05 -07:11:05.1 229.91 15.9 Hydra 2012/01/18 17:00:21 Swift None has been reported. The light curve for this burst had a single peak with a duration of about 30 seconds. Swift slewed immediately to the burst and began XRT observations 112 seconds after the trigger. No source was detected in the initial 2.5 seconds of observations, nor was an detected by the UVOT. However, additional XRT analysis revealed a bright, fading X-ray source within the BAT error circle. GRB 120116A 01:04:58.04 33:55:49.2 126.14 -28.86 Andromeda 2012/01/16 18:06:28 Swift Counterpart detected with i = 24.7. "This burst had two precursor peaks followed by the main, FRED-like peak. The total duration was about 50 seconds. Swift slewed immediately to the burst, with the XRT starting observations 74 seconds after the trigger. A bright, uncatalogued X-ray source was found within the BAT error circle. No optical counterpart was evident in the initial UVOT observations. From the ground, many observers reported only upper limits for the brightness of any OC. However, 11 hours after the burst, observations from the Gemini-North telescope in Hawaii using the izJHK filters revealed a faint object: i=24.7 +/- 0.2 z=24.7 +/- 0.3 J> 23.0 (3-sigma) H=22.8 +/- 0.4 K=21.6 +/- 0.3 It was not clear if the object was actually the GRB afterglow, as the chance alignment of so faint an object within the XRT error circle is a possibility (GCN 12843)." GRB 120114A 21:11:37.03 57:02:08.9 96.32 6 Cepheus 2012/01/14 16:20:09 Fermi 0 This burst was found in ground analysis of a failed trigger event. The burst was also detected by the Fermi/GBM (trigger 348250807). The Swift/BAT light curve for the burst has a duration of about 35 second. The burst occurred too close to the Sun for any followup observations to be undertaken. GRB 120107A 17:53:40 -23:22:18 5.7 1.31 Sagittarius 2012/01/07 09:12:15 Fermi 0 This burst was seen by the Fermi LAT and GBM, and also by Konus-Wind, Suzaku/WAM and MESSENGER/GRNS. The Konus-Wind light curve contained multiple peaks that partially overlapped. The burst duration was about 25 seconds. Both Fermi/GBM Suzaku/WAM and Konus-Wind detected similar shapes and durations for the light curve. score GRB 120106A 04:24:26.65 64:02:17.2 143.81 10.19 Camelopardalis 2012/01/06 14:16:24 Swift 0 This burst showed several overlapping peaks, with emission starting about 8 seconds prior to the trigger. The total duration for the burst was about 20 seconds. XRT began observing about 75 seconds after the trigger. A bright, uncatalogued X-ray source was found within the BAT error circle. Not optical counterpart was seen by the UVOT complimentary observations. GRB 120102A 18:24:53.90 24:42:47.3 52.7 16.5 Hercules 2012/01/02 02:15:55 Swift 0 "This burst showed an initial small peak, followed by a much larger one 32 seconds after the first. The total duration for the burst was about 50 seconds. Swift slewed immediately to the burst, observing with the XRT starting 113 seconds after the trigger. A bright, fading, uncatalogued X-ray source was found within the BAT error circle. In addition, the UVOT found a mag 18.04 object in corresponding observations. This burst also triggered the Fermi/GBM." GRB 111229A 05:05:09.25 -84:42:38.8 297.5 -29.39 Mensa 2011/12/29 22:37:52 Swift 0 "This burst showed 2 or 3 peaks in a light curve that lasted about 25 seconds. Swift slewed immediately to the burst and started XRT observations 83 seconds after the trigger. An uncatalogued X-ray source was found within the BAT error circle. No OC was forthcoming in the UVOT data taken at the same time. The GROND multiband imager was used to obtain data starting about 2 hours after the burst. A new source was detected in all bands at levels much brighter than the DSS2 limit for the field (GCN 12775): g' = 20.50 +/- 0.04, r' = 19.96 +/- 0.03, i' = 19.74 +/- 0.03, z' = 19.58 +/- 0.03, J = 19.01 +/- 0.11. A spectrum was obtained of the GROND object using the Gemini-South telescope. The spectra covered the range from 5900 to 10080 angstroms and showed absorption from Fe II (2586, 2600), Mn II (2606), Mg II (2796, 2803) and Mg II (2853) all at a common redshift of 1.3895 (GCN 12777)." GRB 111228A 10:00:16.01 18:17:51.8 216.33 49.75 Leo 2011/12/28 15:44:43 Swift 0 "This was a strong burst, with a triple-peaked light curve that lasted about 100 seconds. The XRT began observing the burst after 145 seconds, finding a bright, uncatalogued X-ray source within the BAT error circle. In the corresponding UVOT imaging, a candidate afterglow was seen with m = 17.19. Imaging in R and clear filters from the Xinlong TNT confirmed the OC. The images were begun 96 seconds after the GRB trigger and showed a magnitude 16.5 object (GCN 12738, filter not given). The OC was also detected in observations from the 25 cm Tarot CALERN telescope in France. The burst occurred during daylight at that location, so the images were not obtained until 289 minutes after the burst. The OC had R ~ 18 (GCN 12742). A spectrum of this object was obtained using the 6.5 meter MMT. The spectra cover wavelengths from 3400 to 8500 angstroms and show absorption from Fe II and Mg II at a common redshift of z = 0.714 (GCN 12759)." GRB 111225A 00:52:37.21 51:34:19.5 123.12 -11.3 Cassiopeia 2011/12/25 03:50:37 Swift 0 "This burst showed a rise around T-15 seconds, peaking around T-5 seconds, and continuing out to T+150 seconds. The light curve had a FRED shape (GCN 12726). Analysis of the light curve was not done in real time because of a ground-station dropout, so these values are from a later analysis. The XRT began observing the filed 88 seconds after the trigger. A bright, uncatalogued X-ray source was found within the BAT error circle. In the corresponding UVOT data an optical counterpart was seen with m = 19.42. Ground-based observers also detected the optical afterglow. In images taken at TAROT Calern observatory, the OC was seen in co-added images, all of which were taken later than T+1100 seconds. The object has R = 19.1 +/- 0.6. No OC was evident in images taken earlier than that (GCN 12721 and 12722). The OC was also seen by the Super-LOTIS telescope on Kitt Peak. The images commenced 49 seconds after the burst, and the OC is marginally detected in 300 seconds of stacked images (mid-time T+480 seconds) with m = 19.9 +/- 0.2 (GCN 12723). Additional ground-based telescopes also detected the optical afterglow." GRB 111222A 11:56:52.74 69:04:16.2 130.07 47.29 Draco 2011/12/22 14:51:55 Konus-Wind 0 "This was a short, hard burst, lasting only 300 milliseconds. The Konus-Wind light curve showed multiple peaks (GCN 12715). The burst was an IPN localization, using data from Fermi/GBM, Konus-Wind, INTEGRAL/SPI-ACIS, MESSENGER/GRNS Mars Odyssey/HEND and Swfit/BAT (outside the coded field). Swift conducted observations with the XRT starting about 26 hours after the burst. An X-ray source was found within the IPN error box. It was not immediately clear if the source was fading (GCN 12716). Swift also conducted UVOT observations at this time. A faint optical source was detected, consistent with the X-ray source. The source had a magnitude of m = 19.34 +/- 0.03 (unfiltered). This source is also present in the DSS (GCN 12717)." GRB 111215B 14:49:37 16:26:21 17.72 60.65 Bootes 2011/12/15 20:28:06 Konus-Wind 0 This was a long burst, lasting about 75 seconds (according to the Konus-Wind light curve, GCN 12701). The light curve consisted of multiple overlapping pulses. This light curve behavior was also seen in the prompt X-ray emission as seen by the Suzaku/WAM instrument. The duration of this light curve was also about 75 seconds (GCN 12705). GRB 111215A 23:18:13.87 32:29:37.7 101.06 -26.39 Pegasus 2011/12/15 14:04:08 Swift 0 "This was an image trigger, and so the BAT light curve did not show anything significant. Swift slewed immediately to the burst and started XRT observations 418 seconds after the trigger. A bright, uncatalogued X-ray source was found inside the BAT error circle. No UVOT candidate source was found in the initial imaging. No optical counterpart has been reported from any ground observers. However, the MAXI instrument aboard ISS observed the field about 52 minutes before, and then again 40 minutes after the trigger. The source was marginally detected in each set of observations (GCN 12691). This source was also detected at radio wavelengths. It was seen at T+1.46 days by CARMA at 93 GHz (GCN 12710) and at 21.8 GHz at T+3.35 days by the EVLA (GCN 12711)." GRB 111212A 20:41:44.22 -68:36:43.4 326.2 -35.09 Pavo 2011/12/12 09:23:07 Swift 0 This burst was quite weak, with a light curve lasting about 20 seconds. Swift was unable to slew immediately to the burst because of an observing constraint. The constraint was not lifted until 48 minutes after the trigger. When XRT observations were finally able to be made, at ~T+54 minutes, an uncatalogued X-ray source was seen to lie within the BAT error circle (GCN 12669). Additional analysis of the BAT light curve showed a FRED-like pulse that began about 2 seconds before the trigger, peaked about 6 seconds after, and dropped below background around 60 seconds post-trigger. No optical counterpart has been reported for this burst. GRB 111211A 10:12:21.84 11:10:55.52 228.19 49.42 Leo 2011/12/11 22:17:33 SuperAGILE 0 "This burst lasted about 15 seconds and had a double-peaked structure, with some substructure superimposed. This field was observed using the GROND multi-object imager on the 2.2 meter telescope at La Silla about 8.5 hours after the burst. A source was found within the SuperAGILE error circle with r’ = 19.0, brighter than the DSS limit. The source is not seen on either the DSS red plate or in SDSS r images (GCN 12668). Subsequent imaging using the StanCam on the Nordic Optical Telescope (NOT) showed that the object had faded in the ~20 hours since the GROND images were taken. This suggests that the object is the afterglow of the GRB (GCN 12675). A spectrum of the source was obtained using the VLT/X-Shooter about 1.3 days after the burst. The spectra covered from 3000 to 25000 angstrom. The spectrum shows a smooth continuum with absorption from Fe II, Mg II and Ca II, all at a redshift z = 0.478. Weak emission from [O III] and Halpha are also seen at this redshift (GCN 12667). This source was also detected by the Swift/XRT in observations done approximately 18 hours after the trigger (GCN 12673)." GRB 111210A 12:45:54.02 -07:09:56.3 300.5 55.68 Virgo 2011/12/10 14:37:03 Swift 0 "This burst had a double-peaked structure and lasted about 2.5 seconds. Swift slewed immediately to the burst, beginning XRT observations 61 seconds after the trigger. An uncatalogued X-ray source was found within the BAT error circle. No optical counterpart was in contemporaneous UVOT imaging. A faint afterglow candidate was reported in imaging done using the Gemini-North telescope. The data were taken in r and z about 39 minutes after the trigger. The source had r~23 and was within the XRT error circle (GCN 12657). These sources are also present in the SDSS images of the filed, with magnitudes consistent with those measured at Gemini. Thus they are likely to be candidate host galaxies, but with little or not contribution from the burst itself. Colors suggest that if associated with either of these objects, the burst would have a redshift z < 4 (GCN 12661). These sources were also detected in images taken with the GROND multi-band imager (GCN 12662)." GRB 111209A 00:57:23.08 -46:48:01.7 299.91 -70.29 Phoenix 2011/12/09 07:12:08 Swift 0 "This burst was unusual in that it caused two BAT triggers, the second one occurring 424 seconds after the first, and with much higher intensity. The initial burst was 324 seconds long. The satellite slewed immediately to the burst and began XRT observations 419 seconds after the first BAT trigger. A bright, uncatalogued x-ray source was seen within the BAT error circle. In contemporaneous UVOT observations, an optical source overlying the XRT source with a magnitude of m = 18.1. The optical afterglow was also reported by ground-based observers. The TAROT 25 centimeter robotic telescope at La Silla, Chile, started observing 358 seconds after the trigger. The source had R ~ 16.2 at T+680 (GCN 12633). The source was also detected in the near infrared, with H = 14.7 +/-0.2, using the REM 60 cm telescope, also on La Sila (GCN 12634). In addition, several other ground-based observers confirmed the presences of the optical afterglow. As mentioned, this burst was unusual in that it triggered the BAT two times. The emission from the burst peaked around 900 seconds, then dropped after T+1100 seconds. Nonetheless, emission was detectible beyond 10ks after the trigger. The XRT light curve, which extends out to about 25ks (~7 hours) after the burst, shows high variability with many flares present. There was a precipitous decrease in flux after this time, though emission was still detectible. The UVOT also observed the afterglow, noting a brightening by 0.6 mag at the end of the first orbit that corresponded to a flare in the x-ray light curve. The optical counterpart was detected in all seven filters of the UVOT, and the other filters all show complicated, flaring light curves as well (GCN 12641). A spectrum of the afterglow was obtained by the VLT/X-Shooter at ~T+18hr. Four spectra, each with 1200 seconds of exposure time, were obtained. They cover from 0.3 to 2.5 micron, with a resolution ranging from 4500 to 7500. The spectra show a smooth continuum in the optical/UV with several absorption features present at correspond to Fe II, Mg II, Mg I, Ca II H and K, all at z = 0.677 (GCN 12648)." GRB 111208A 19:20:51.6 40:40:07 72.62 12.17 Lyra 2011/12/08 08:28:11 Swift 0 "This burst was found in ground analysis from a failed trigger event. Its significance was 10.1 sigma and it was coincident with the Fermi/GBM trigger 345025690. The duration of the burst was about 20 seconds. Subsequent XRT/UVOT observations taken about 7 hours after the burst showed an uncatalogued x-ray source, but no optical counterpart. No fading of the x-ray source was evident in the observations obtained (GCN 12631). " GRB 111207A 06:11:41.7 -39:30:16 246.56 -24.11 Columba 2011/12/07 14:16:59 Swift 0 This burst was found in ground analysis. The detected count rate increase was not strong enough to trigger automatically, but a significant source was nevertheless found. The burst showed a single pulse lasting about 3 seconds. GRB 111205A 08:57:57 -31:58:20 255.95 8.89 Pyxis 2011/12/05 13:10:50 INTEGRAL 0 This burst was localized by the IPN, including INTEGRAL, Konus-Wind and Mars Odyssey. Additional observations by Konus-Wind showed a light curve with a hard bright burst lasting about 20 seconds, with weaker emission continuing for another ~65 seconds (GCN 12627). Followup observations by Swift/XRT were carried out about 55 hours after the trigger. Thought the XRT field of view is smaller than the error box of the IPN localization, an uncatalogued x-ray source was detected which is possibly the GRB afterglow. The source was outside the UVOT field of view, but DSS images showed an optical source within the XRT field (GCN 12630). GRB 111204A 22:26:30.99 -31:22:30.5 16.45 -58.25 Piscis Austrinus 2011/12/04 13:37:28 Swift 0 This was a double-peaked burst lasting about 80 seconds. The satellite slewed immediately to the burst and started XRT observations 160 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. No optical candidate was seen by contemporaneous UVOT observations, nor has any optical counterpart been reported by ground-based observers. GRB 111201A 12:41:54.48 32:59:16.5 141.73 83.79 Canes Venatici 2011/12/01 14:22:45 Swift 0 "This burst was detected in ground analysis. It was from the failed event data of BAT trigger 508800 and had a significance of 10.8 sigma. The burst was contemporaneous with Fermi/GBM trigger 344442167. The duration of the burst was about 20 seconds. Subsequent XRT data obtained about 7.5 hours after the trigger detected the x-ray afterglow of the burst (GCN 12609). Additional observations about a day later showed that the source had faded, suggesting strongly that it was indeed the burst afterglow (GCN 12611)." GRB 111129A 20:29:44.15 -52:42:46.5 345.82 -35.95 Indus 2011/11/29 16:18:14 Swift Optical counterpart seen with m = 19.06 "An Earth-limb constraint prevented Swift from slewing to this burst for 52 minutes. The light curve had a single FRED-like peak lasting about 10 seconds. Early XRT and UVOT were not available due to the constraint. When the constraint was lifted, the satellite began observing the burst at T+55 minutes. An uncatalogued x-ray source was found within the BAT error circle (GCN 12398). No optical counterpart was seen in corresponding UVOT observations, with a limiting magnitude around m = 18 (GCN 12397). No optical candidate has been reported from any ground-based observations." GRB 111123A 10:19:23.14 -20:38:43.1 261.37 29.7 Hydra 2011/11/23 18:13:21 Swift None has been reported. "This burst was quite long, with a total duration of about 170 seconds. The BAT light curve showed several overlapping peaks beginning around T-10 seconds and continuing out to about T+30, and then a very strong peak from T+60 to T+160. Swift slewed immediately to the burst and started observing with the XRT 99 seconds after the trigger. A bright, uncatalogued x-ray source was seen. No optical afterglow was seen in the initial UVOT data. No optical detections of this burst afterglow have been reported from the ground. However, a faint NIR source was seen at K=19.4 +/- 0.3 in observations started about 11.5 hours after the trigger. No corresponding sources were seen in either J or H images (GCN 12593). " GRB 111121A 10:19:02.68 -46:40:14.3 277.58 8.56 Vela 2011/11/21 16:26:24 Swift None has been reported. "This burst lasted about one second and showed a single spike in its light curve. The satellite slewed immediately to the burst and began observing with the XRT 77 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. No optical afterglow was seen in the initial UVOT data. Imaging of the field by the Magellan telescope were hampered by the proximity of the bright star to the GRB field. A faint source was seen on the edge of the XRT error circle, but diffraction spikes from the star complicated a magnitude being determined, or even a determination of whether the source was fading (GCN 12583)." GRB 111117A 00:50:46.257 23:00:40.01 122.73 -39.86 Andromeda 2011/11/17 12:13:41 Swift Optical counterpart seen with R = 23.1. "This short burst had a double-peaked structure and a duration of only 0.6 seconds. Swift slewed immediately to the burst and began observing with the XRT after 77 seconds. An uncatalogued x-ray source was found within the BAT light curve. No optical counterpart was found in the initial UVOT data. The limiting magnitude from the UVOT data was b > 20.0 (GCN 12569). Observations from the NOT in R showed a faint object, with R = 23.1 +/- 0.3 just outside the XRT error box. These observations were taken about 8 hours after the burst. The observers suggest this object is possibly the afterglow or host galaxy of the GRB (12563). These observations are confirmed by a set taken with the TNG (GCN 12570). Additional observations made using the Magellan telescope also showed the object, but at a somewhat fainter level, with r = 23.9 +/- 0.15, suggesting that it might have faded in the ~5.5 hours between sets of observations. Gemini observers reported a similar fading in their observations taken about 17 hours after the burst. The object had faded to r’ = 23.99 +/- 0.11 (GCN 12567). Followup observations from the NOT on the night after the burst also show some evidence for fading between the two nights, suggesting that the GRB light contributed to the galaxy brightness shortly after the burst (GCN 12572). This burst was also detected by the Fermi/GBM with light curve characteristics similar to those from the BAT (GCN 12573). The afterglow was seen in ToO observations made with the Chandra X-ray Observatory (GCN 12580). " GRB 111109A 07:52:47 -41:35:54 256.29 -7.28 Puppis 2011/11/09 02:57:46 Swift none has been reported. The BAT light curve for this burst showed several peaks with a total duration of 20 seconds. The satellite could not slew to this burst because of an observing constraint, which was in effect for 49 minutes past the trigger. After the constraint was lifted, the XRT began observing the field, but no x-ray afterglow was detected (GCN 12549). GRB 111107A 08:37:56 -66:30:22 281.28 -15.02 Volans 2011/11/07 00:50:23 Swift Counterpart seen with R = 19.5 z = 2.839 "The light curve for this burst had a simple FRED-like structure with a duration of around 15 seconds. The XRT began observing the field 65 seconds after the burst, finding a bright, fading, uncatalogued x-ray source. The UVOT also detected the afterglow, with a magnitude of 19.21 (unfiltered). The afterglow was also seen from the ground. The PROMPT4 and PROMPT5 telescopes at Cerro Tololo, Chile imaged the field in R and I, respectively, about 15 minutes after the trigger. Their exposures showed the object at R = 19.467 and I = 18.444 (GCN 125235). The GROND multi-band imager on the MPI/ESO 2.2 meter telescope also detected int he afterglow at r’ = 21.3 +/- 0.1 at a time 2.6 hours after the trigger (GCN 12536). The Gemini-South telescope obtained a spectrum of this object 4.2 hours after the trigger. Their spectrum covers the range from 4160 to 8140 angstroms and shows a damped Lyman-alpha absorber, as well as narrow lines of C IV, Al II and C II at the common redshift of z = 2.893 (GCN 12537). These spectral results were confirmed by a VLT/X-shooter spectrum, with the additional mention of a Mg II absorber at z = 1.998 (GCN 12542)." GRB 111103B 17:42:46.91 01:36:36.3 26.39 15.98 Ophiuchus 2011/11/03 10:59:03 Swift None has been reported. "This burst had a complex light curve, with a bright main peak that persisted for about 20 seconds after the trigger, and then continued activity out to at least 150 seconds after the trigger. Swift slewed immediately to the burst and began observing with the XRT 59 seconds after the trigger, finding a bright, uncatalogued x-ray source within the BAT error circle. No afterglow candidate was seen by the UVOT. This burst was also observed by Konus-Wind, which saw a 15 second long light curve with continued weak activity out to 40 seconds after the trigger. The activity after this which was detected by Swift was lost in the Konus-Wind data because of increasing background counts from a solar flare (GCN 12532). " GRB 111103A 21:48:29 -10:32:49 44.96 -43.96 Capricornus 2011/11/03 10:35:13 Swift None has been reported. "The light curve for this burst had multiple peaks and lasted about 20 seconds. Moon observing constraint prevented Swift from slewing immediately to this burst. The constraint was in effect through 20:12 UT on Nov 5. This burst was also detected by Fermi/GBM. The light curve showed the same multiply-peaked light curve as the BAT, and a duration of about 12 seconds. Fermi measured a power-law spectrum with an exponential cutoff: alpha = -0.43 +0.16/-0.15, Epeak = 152.2 +16.1/-12.8 (GCN 12529)." GRB 111029A 02:59:07.82 57:06:36.9 139.63 -1.56 Perseus 2011/10/29 09:44:40 Swift None has been reported. "This burst had a duration of at least 20 seconds and a complex structure. Swift slewed immediately to the burst and began observing with the XRT 178 seconds after the trigger. An uncatalogued x-ray source was found in the promptly downloaded data. No optical counterpart was seen by the UVOT. Only upper limits have been reported; no optical counterpart has been seen." GRB 111026A 16:17:01.5 -47:26:05.1 334.87 2.28 Norma 2011/10/26 06:47:29 Swift None has been reported. The light curve for this burst had a double-peaked structure and a duration of 1.5 seconds. A Sun observing constraint prevented Swift from slewing to this burst. The constraint will remain in effect until 12 January, 2012. As a result, there will be no XRT or UVOT data before this time. GRB 111022B 07:15:51.49 49:41:00.4 167.76 24.14 Lynx 2011/10/22 17:13:04 Swift None has been reported. "This burst was an image trigger, and so the BAT light curve does not show anything. Swift slewed immediately to the burst and began observing with the XRT after 137 seconds post trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. No optical afterglow was seen in the initial UVOT data, nor has any been reported in followup ground-based observations. " GRB 111022A 18:23:27.40 -23:40:20.6 8.75 -4.81 Sagittarius 2011/10/22 16:07:04 Swift None has been reported. "This burst lasted about 15 seconds and had a single peak. Swift slewed immediately to the burst and began observing with the XRT 76 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. No optical counterpart was seen in the initial UVOT images. No afterglow candidate has been reported from ground-based observers." GRB 111020A 19:08:12.73 -38:00:42.4 359.35 -19.4 Corona Austrina 2011/10/20 06:33:49 Swift None has been reported. "This burst had a single peak lasting only about 0.5 seconds. The XRT began observing 73 seconds after the trigger, finding an uncatalogued x-ray source within the BAT error circle. No optical counterpart was found in the initial UVOT products. Only upper limits for the brightness of any OC have been reported from ground-based observers." GRB 111018A 18:05:57.33 -03:54:25.9 24.19 8.28 Serpens 2011/10/18 17:26:24 Swift None has been reported. This burst had two weak peaks, one at T0 and the other near T+30. The total burst duration was about 40 seconds. Swift slewed immediately to the burst; an x-ray source was found, however, because its position was significantly different from the BAT position it was thought that the XRT had possibly fixed on a cosmic ray. However, further observations confirmed that this position was essentially correct (GCN 12453). The initial XRT observations were begun 123 seconds after the GRB trigger. No optical counterpart was seen in the initial UVOT data. GRB 111017A 00:32:24 -07:36:00 109.05 -69.96 Cetus 2011/10/17 15:45:23.72 Fermi 0 The GBM light curve ad a single symmetric peak with emission extending up to 1 MeV. The burst was bright enough to trigger the spacecraft to repoint. Its duration was about 11 seconds. The spectrum was fit by a Band function, with alpha = -0.91 +/- 0.02, beta = -2.7 +/- 0.40 and Epeak = 692.5 +.- 48.3 keV. GRB 111016B 19:22:00 -04:34:39 32.32 -8.88 Aquila 2011/10/16 22:41:40 Konus-Wind 0 This was an IPN localization, with data from Konus-Wind, Mars Odyssey/HEND, MESSENGER/GRNS, RHESSI and Swift/BAT contributing. The burst was outside the coded field of view of the BAT instrument, and so did not trigger a Swift burst. The light curve of this burst, as reported from Konus-Wind had multiple peaks and lasted about 150 seconds. Emission was observed up to about 5 MeV. GRB 111016A 10:15:13 27:28:32 203.14 55.44 Leo 2011/10/16 18:37:04 Swift Counterpart seen with i' = 22.1 "This burst consisted of at least 7 distinct peaks that lasted at least 230 seconds. There was even a possible additional peak at T+600 seconds. Swift slewed immediately to the burst and started observing with the XRT 180 seconds after the trigger. A bright x-ray source was found within the BAT error circle. No optical counterpart was found in the prompt UVOT data. Additional UVOT images also failed to find a counterpart to the x-ray source detected by XRT. However, a faint source was marginally detected in the white filter, consistent with the sources reported by ground-based observers, discussed below (GCN 12446). A possible optical counterpart was reported from Palomar 60 images. These were done in r’, i’ and z’ approximately 16.9 hours after the trigger. An extremely faint object was marginally detected in i’ at 22.1+/- 0.3 mag. No detections were made in the other filters, so it is not clear that this object is related to the GRB (GCN 12444). This source was confirmed in observations from the Gemini-North telescope in JHK images. The source was detected in all three filters 19.8 hours after the burst. Magnitudes for the source are estimated to be K ~ 20.4 +/- 0.2 (GCN 12447). " GRB 111008A 04:01:48 -32:41:18 232.58 -48.71 Eridanus 2011/10/08 22:12:58 Swift Counterpart seen with r = 22.8 z = 4.9898 "The light curve for this burst had 3 sets of peaks, lasting about 70 seconds total. Swift slewed immediately to the burst, starting XRT observation 92 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. No optical afterglow candidate was seen with the UVOT imaging. Images taken using the Gemini-South telescope in r-band did locate an object within the XRT error circle. The magnitude of the object was r ~ 22.8 in data acquired about 5 hours after the trigger (GCN 12426). This object was confirmed in images taken using the Nordic Optical Telescope approximately 2 hours after the Gemini imaging (GCN 12427) and by GROND multi-band imaging taken about 1.3 hours after (GCN 12428). A Gemini-South spectrum covering the range between 3900 and 8100 angstroms showed a single deep absorption feature near 7300A and a cutoff in the flux near 5500A. Taking these to be from a damped Lyman-alpha system implies a redshift of z ~ 5. Additional absorption features are seen from Lyman-beta, OI (1302), CII (1334) and SiII (1260.5), all at a common redshift of z = 5.0 (GCN 12429). A spectrum obtained at the VLT confirms these lines, and several others, at a redshift of z = 4.9898 (GCN 12431)." GRB 111005A 14:53:08 -19:43:49 338.34 34.64 Libra 2011/10/05 08:05:14 Swift None has been reported. "This burst had a single peak lasting about 20 seconds. Swift was not able to slew to the burst because of a Sun constraint. No slew will be possible until 25 December, 2011, so no XRT/UVOT data will be forthcoming. The position of the burst is close to a z=0.01326 galaxy, which lies within the BAT error circle (GCN 12414). Several attempts to detect the afterglow from the ground were made from various observatories, but perhaps due to the close proximity of the burst to the Sun, no counterpart has been reported." GRB 110928B 18:35:48 -19:19:41 13.95 -5.37 Sagittarius 2011/09/28 19:17:20 Swift None has been reported. This burst corresponds to the MAXI source J1836-194, lying only 70 arc-seconds away. The BAT trigger was an image trigger, and the light curve shows nothing as is usual for image triggers. Observing constraint prevented Swift from slewing immediately to the source. GRB 110928A 17:11:01 36:34:12 60.2 35.1 Hercules 2011/09/28 01:51:31 Swift None has been reported. "An Earth-limb constraint prevented Swift from slewing to this burst for 52 minutes. The light curve had a single FRED-like peak lasting about 10 seconds. Early XRT and UVOT were not available due to the constraint. When the constraint was lifted, the satellite began observing the burst at T+55 minutes. An uncatalogued x-ray source was found within the BAT error circle (GCN 12398). No optical counterpart was seen in corresponding UVOT observations, with a limiting magnitude around m = 18 (GCN 12397). No optical candidate has been reported from any ground-based observations." GRB 110924A 15:38:59 -66:18:29 318.68 -8.7 Triangulum Australe 2011/09/24 09:03:20 Swift GRB 110921A 19:36:23.61 36:19:43.8 70.09 7.49 Cygnus 2011/09/21 13:51:20 Swift Optical afterglow detected at m = 20.2 "This burst had a “raggedâ€� single peaked light curve lasting about 10 seconds. The XRT began observing the field beginning 122 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. No optical counterpart was detected in contemporaneous UVOT imaging. Optical images from the Xinglong TNT telescope in China starting about 8 minutes after the trigger showed a new source within the XRT error circle. The estimated magnitude of the object in the unfiltered images was m = 20.2 (GCN 12377). Images at the MITSuME 50 cm telescope of the Akeno Optical Observatory, Japan also showed a possible afterglow. Images in g and R did not show the candidate, but the earliest I images did show a marginal detection. The images were collected from T+108 seconds to T+348 seconds (GCN 12378). " GRB 110918A 02:10:09.27 -27:06:22.0 217.38 -72.5 Fornax 2011/09/18 21:27:02.856 Konus-Wind 0 "This burst was localized by the IPN, including missions INTEGRAL/SPI-ACS, Konus-Wind, Mars Odyssey/HEND and MESSENGER/GRNS. The Knous-Wind light curve showed an extremely bright, short pulse with a hard spectrum. This was followed by three overlapping weaker peaks over the subsequent 25 seconds. A weaker decaying phase of the burst continued out to T+250 seconds, at which point the Konus-Wind measurements ceased (GCN 12362). In ToO observations from Swift/XRT taken about a day after the burst a new X-ray source is seen, though it is outside the IPN error box. No fading of the burst was noted over the ~2 hours of observations, but it seems unlikely that a bright uncatalogued x-ray source so close to the IPN burst is unrelated to the burst (GCN 12364). Ground-based observers reported an optical counterpart for this burst. From the Isaac Newton Telescope on La Palma, Canary Islands a bright point source was seen with R = 19.0 to 19.5 in images obtained 29 hours after the trigger. The object was quite close to the position of the x-ray afterglow seen with Swift (GCN 12365). Additional observations from GROND at about the same time confirmed the presence of the Isaac Newton object in the NIR: J = 18.7 +/- 0.1. The optical channels did not show the object because of the smaller field of view in those filters: the observations were pointed at the original IPN coordinates, which seem to be slightly off (GCN 12366). Spectroscopic observations were done using the Gemini-North telescope. The spectrum showed a power-law continuum and absorption features of Mg II (2796A/2804A), Mg I (2853A) and Ca II (3935A/3970A) at a common redshift of z = 0.982 (GCN 12368)." GRB 110915B 05:10:13.13 01:55:57.9 198.96 -21.4 Orion 2011/09/15 18:24:19 SuperAgile None has been reported. "This burst lasted about 18 seconds. Its light curve displayed a single peak. Approximately ten hours after the trigger a Target of Opportunity observation was made by Swift/XRT. An uncatalogued X-ray source was found within the AGILE error box (GCN 12348). In subsequent imaging done out to five days past the trigger the X-ray source was seen to fade, suggesting that it is indeed the X-ray afterglow of the GRB (GCN 12372). An optical afterglow candidate was reported with R = 22.8 based upon combining 46 x 120 second exposures from the 1.5 meter OSN telescope of the Sierra Nevada Observatory in Spain. The mid-time for these observations was 9.59 hours after the burst trigger (GCN 12350). This object was also observed using the GROND multi-band imager on the ESO 2.2 meter telescope, La Silla, Chile. The GROND images showed that the object had r’ = 23.2 +/- 0.1 in images taken 2.5 days after the burst. Thus the object shows no decay over the two days between observations, suggesting that it is not the GRB afterglow (GCN 12356)." GRB 110915A 20:43:17.80 -00:43:23.1 45.85 -25.03 Aquarius 2011/09/15 13:20:44 Swift "Swift slewed immediately to this burst, which had a duration of 95 seconds. The light curve showed multiple peaks. The XRT began observing the field 76 seconds after the trigger, finding a bright, uncatalogued x-ray source. No optical counterpart was detected in contemporaneous observations with the UVOT. The limiting magnitude was around m = 18. Ground-based imaging also failed to find any optical afterglow." GRB 110906A 19:47:33.9 26:12:32 62.42 0.45 Vulpecula 2011/09/06 12:25:13 Swift This was a BAT slew trigger, the result of a 7.8 sigma and 4.7 sigma image detection in the energy bands from 15-150 keV and 15-50 keV, respectively. Moon constraint prevented the immediate follup of this source, and no corroborating observations have confirmed it. No future followup observations are planned. GRB 110905A 18:35:43.44 -19:19:10.5 13.95 -5.35 Sagittarius 2011/09/05 05:48:40 Swift Optical afterglow detected at R = 16. "The BAT light curve for this burst was not immediately available, nor could the satellite slew to the burst because of a Moon constraint. No XRT/UVOT data were possible until after September 8. The KAIT telescope at Lick Observatory, Mt. Hamilton, California started an automated image sequence approximately 30 minutes after the trigger. A new object was found within the BAT error circle with R = 16 (GCN 12328). This same object was reported as a possible source to the X-ray transient detected by MAXI, a black hole candidate with known optical and radio counterparts. The MAXI observations suggest that this object was likely due to high energy emission from this known source, rather than an actual GRB (GCN 12329). The same object was detected using the Xinglong TNT telescope about 5.6 hours after the burst trigger. An R ~ 15.5 object was seen (GCN 12330)." GRB 110903A 13:08:15.77 58:58:53.5 118.84 58.01 Ursa Major 2011/09/03 02:39:55 INTEGRAL "This burst had a very long duration, about 400 seconds. The light curve had three main peaks, one beginning at T0, the second 200 seconds later, and the third 100 seconds after that. This source was detected by Konus-Wind, with the same three peaks observed (GCN 12323). This burst was also observed by Swift/XRT starting not quite 9.5 hours after the trigger. An x-ray source was detected within the INTEGRAL error box. In just over an hour of observations the source showed no clear signs of fading (GCN 12324). The burst was also seen in the Fermi/GBM (GCN 12326)." GRB 110827A 10:56:22 53:47:13 153.47 55.98 Ursa Major 2011/08/27 00:01:52 Swift None has been reported. This burst lasted about 30 seconds and had a complex light curve. Sun constraint prevented Swift from slewing to the burst, with the constraint not being lifted until Sept 5, 2011. Thus no prompt XRT or UVOT data was available. GRB 110825A 2:59:35.1 15:24:25 162.95 -37.31 Aries 2011/08/25 06:22:11.44 Fermi 0 "This was an IPN localized event, with Fermi/GBM, AGILE/MCAL, MESSENGER/GRNS, Mars Odyssey/HEND, Suzuku/WAM and Swift/BAT contributing to the triangulated coordinates. The Fermi/GBM light curve lasted about 4 seconds. A Swift Target of Opportunity observations was made starting about 23 hours after the GRB. In 2.9 kiloseconds of observations (~48 minutes) an x-ray source was seen within the IPN error box. There was no known source at the position of this source, though current catalogs do not go deep enough to have included it. No UVOT source was found to v > 19.19 (GCN 12308). A possible afterglow with R~23.6 was obtained using the Nordic Optical Telescope (NOT) /ALFOSC. The imaging was done in poor weather conditions and brightening morning twilight, so only one image was obtained and it was not possible to determine if the object was fading (GCN 12311). The 2.4 meter Gau-Mei-Gu telescope in Yunan, China was used to observe the field approximately 19 hours after the burst. The R-band object reported in the NOT observations was not present to a limiting magnitude R~23.9 (GCN 12314). No optical afterglow was seen in early times, within the first 5 to 15 minutes, as reported from the ROTSE-IIId telescope of the Turkish National Observatory at Bakirlitepe, Turkey. Limiting magnitudes are between 15.6 at early times and 14.4 in the later observations (GCN 12313)." GRB 110820B 10:30:20 -54:36:16 283.36 2.82 Vela 2011/08/20 21:27:48 Konus-Wind None has been reported. "This was an IPN localization utilizing data from Konus-Wind, MESSENGER, RHESSI and Swift. This Konus-Wind light curve shows two major bursting episodes separated by approximately 100 seconds. Weaker and softer emission was detected between these events. The total burst duration was about 200 seconds, with emission seen up to around 10 MeV. " GRB 110820A 22:52:46.14 70:17:54.5 113.19 9.71 Cepheus 2011/08/20 17:38:27 Swift None has been reported. Swift slewed immediately to this burst. It had a single peak in its light curve, and a duration of 10 seconds. The XRT began observing the field 79 seconds after the trigger, finding an uncatalogued x-ray source within the BAT error circle. No optical counterpart was seen in contemporaneous UVOT observations. GRB 110818A 21:09:21.17 -63:58:53.1 330.71 -39.11 Pavo 2011/08/18 20:37:49 Swift Counterpart seen at R = 22.3. z = 3.36 "This burst had several peaks and a duration of around 60 seconds. Earth-limb constraint prevented the satellite from slewing for four minutes. The XRT therefore began observing the field after a delay of 380 seconds. It detected a fading, uncatalogued x-ray source within the BAT error circle. No optical counterpart was seen in the initial UVOT imaging, which commenced 856 seconds after the trigger. From the ground, imaging with the ESO VLT on Paranal, Chile showed an optical candidate with R = 22.3. A spectrum consisting of four 1200 second exposures was obtained for this object. The spectra covered from 3000 to 25,000 angstroms. The spectrum shows absorption from Si II, C IV, Al II, Ca H&K and Mg I. Emission is also seen from [O III]. All these features are at a redshift of z = 3.36 (GCN 12284)." GRB 110815A 05:41:11.2 32:36:31 176.37 1.12 Auriga 2011/08/15 09:40:57 Fermi 0 This IPN localized burst included data from SuperAGILE, Konus-Wind, MESSENGER, Mars Oddysey, RHESSI, Suzaku and Swift. The Konus-Wind light curve had two peaks separated by about 13 seconds. The total burst duration was 20 seconds. Emission was seen up to 8 MeV and the spectrum was best fit by a Band function with alpha = -0.85 +/- 0.1, beta = -2.5 +0.2/-0.3 and Epeak = 251 +/- 25 keV (GCN 12278). GRB 110812A 23:53:38.15 72:12:23.32 118.49 9.83 Cepheus 2011/08/12 00:20:08 Fermi 0 This burst lasted about 30 seconds and a multi-peak structured light curve. GRB 110808B 17:44:43.4 37:44:47 63.16 28.76 Hercules 2011/08/08 15:44:53 Konus-Wind None has been reported. "The light curve for this burst consisted of the single hard pulse lasting about half a second. The burst triggered Konus-Wind and was localized by the IPN. The spectrum was best fit by a power law with exponential cutoff: alpha = -1.13 +/- 0.08 and Epeak = 2960 +1217/-796 keV (GCN 12271). The missions contributing to the IPN localization were Konus-Wind, Mars Odyssey, MESSENGER and RHESSI (GCN 12269)." GRB 110808A 03:49:04.28 -44:11:40.3 250.57 -50.69 Horologium 2011/08/08 06:18:54 Swift Counterpart seen at m = 19.93 z=1.348 "This burst had a single peak and lasted about 10 seconds. Swift slewed immediately to the burst and began observing with the XRT after 111 seconds. A bright, uncatalogued and fading x-ray source was found. The UVOT also detected an optical afterglow candidate in the initial data. The OC had a magnitude of 19.93 (unfiltered). A spectrum of the OC was obtained using the ESO VLT/X-shooter. The spectrum was obtained 3 hours after the trigger and showed emission lines from [O II], [O III] and H-alpha, and absorption from Mg II and Fe, all at the common redshift of z = 1.348 (GCN 12258)." GRB 110807A 18:34:52.20 -08:45:57.5 23.25 -0.34 Scutum 2011/08/07 19:57:46 Swift None has been reported. "This was an extremely short burst, with the light curve occupying only one time-tin, i.e., the burst lasted no more than 0.064 seconds! Nonetheless, the count rate was large enough to be significant, and when the satellite slewed over and began observing with the XRT 329 seconds after the trigger and x-ray source was found within the BAT error circle. The source was close to a known x-ray source, which was only 6.6 arcsedonds away. It was not clear from the initial data whether or not the new source was fading. No optical counterpart was seen in the prompt UVOT data, which was taken beginning 332 seconds after the trigger. No obvious optical afterglow was reported from ground observations. However, images of the field from the 6 meter BTA revealed one object within the XRT error circle at R = 23.44. Another object was seen just outside the error circle, which corresponds to the second x-ray source seen by the XRT (GCN 12254)." GRB 110802A 02:57:49 32:35:34 151.62 -23.15 Perseus 2011/08/02 15:19:17 Konus-Wind None has been reported. http://www.ioffe.ru/LEA/GRBs/GRB110802_T55156/ "This burst was detected and localized the the Interplanetary Network. Contributing satellites and instruments included Konus-Wind, MESSENGER GRNS, Mars Odyssey HEND, Swift BAT (outside coded region) and Suzaku WAM. The Konus-Wind light curve showed a double-peaked pulse lasting 0.6 seconds, with emission seen up to about 10 MeV. The spectrum was best-fit by a power law with exponential cutoff: alpha = -0.63 +0.31/-0.25, Epeak = 3451 +2256/-1086 keV (GCN 12249)." GRB 110801A 05:57:44.73 80:57:21.6 132.62 24.7 Camelopardalis 2011/08/01 19:49:42 Swift Counterpart seen at m = 18.03 "The light curve for this burst had several weak peaks and a duration of about 70 seconds. Swift slewed immediately and began observing with the XRT 99 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. UVOT observations also detected an afterglow in the initial data products. The OC had a magnitude of m = 18.03 (unfiltered). The UVOT imaging began 108 seconds after the trigger. The optical afterglow was also seen in observations from the ground. The ROTSE-III telescope of the Turkish National Observatory in Bakirlitepe began observing the field 195 seconds after the burst. They detect the OC at m~15.0 (GCN 12229). Additional imaging was done using the Theuringer Landessternwarte Tautenburg 2.1 meter Schmidt telescope beginning approximately 20 minutes after the GRB trigger. R-band imaging showed the OC at the same position as the UVOT source. No information was given about the magnitude of the source in these images (GCN 12230). A spectrum of the afterglow was obtained using the OSIRIS instrument on the 10.4 meter GTC at La Palma, Canary Islands.The two 900 second exposures and a single 600 second one cover wavelengths from 3600 to 7500 angstroms. The spectra show absorption features from C II, Si IV, Si II, C IV, Fe II, Al II, Al III, Ni II, Zn II and Mn II. Also seen are fine structure Fe II* and Ni II*. All the lines are at a common redshift of z = 1.858. Intervening systems are seen in Mg II absorption at Z = 1.246 and z = 0.745. The spectra were obtained 7.7 hours after the burst trigger (GCN 12234). " GRB 110731A 18:42:01.00 -28:32:10.6 6.22 -10.7 Sagittarius 2011/07/31 11:09:30 Swift Counterpart seen at m = 15.80 z=2.83 "This burst lasted about 20 seconds. Its light curve had multiple peaks. Swift slewed immediately to the burst and began observing the field 66 seconds after the trigger. A bright, uncatalogued x-ray source was found. In observations begun 75 seconds after the trigger the UVOT also detected an afterglow candidate, with m = 15.80. The burst was also seen by Fermi, both in the LAT (GCN 12218) and the GBM (GCN 12221). The LAT observations show emission above 100 MeV to better than 10 sigma significance. The position of the burst was only 6 degrees from the LAT boresight. The GBM light curve had a single pulse lasting 7.3 seconds. Ground-based observations from the Faulkes Telescopes in Hawaii and Australia both began at T+110 seconds and T+182 seconds, respectively. An uncatalogued fading source was found coincident to the UVOT position. The magnitude of the source was R = 16.4 at T+28 minutes (GCN 12216). This source was further confirmed from several additional ground-based telescopes. Spectroscopic observations were made using the Gemina-North telescope and GMOS spectrograph. The observations totaled 3600 seconds and covered from 3800 to 6650 angstroms. Broad Lyman-alpha absorption was seen, as well as absorption from O, C, Si and Al at the common redshift of z = 2.83. At the time of these observations, approximately 22 hours after the GRB, the object had an R magnitude of 22.0 (GCN 12225)." score GRB 110726A 19:06:51.87 56:04:16.3 86.54 20.18 Draco 2011/07/26 01:30:40 Swift Optical afterglow detected at m = 17.80 z=1.036 "This burst had a single peak with a duration of 10 seconds. Swift slewed immediately to the burst and started observing with the XRT 58 seconds after the trigger. A fading, uncatalogued x-ray source was seen. No optical counterpart was detected with the UVOT in the initial data. However, subsequent analysis of the image did show an optical candidate with m = 17.80 (unfiltered - GCN 12199). From the ground, the ROTSE-III telescope located at the Turkish National Observatory, Bakirlitepe, Turkey, began imaging the field 13.8 seconds after the GRB trigger. The unfiltered images showed an object with m = 16.9 that is not present in the DSS of the field (GCN 12197). The afterglow was also observed with the Liverpool 2 meter telescope in the R and I bands (GCN 12198): Mid time from Total Exp Filter Magnitude trigger (min) (s) ------------------------------------------------ 14.7 10 R 19.0 +/- 0.1 30.0 60 R 19.6 +/- 0.1 20.1 30 I 18.6 +/- 0.1 33.0 60 I 19.1 +/- 0.1 ------------------------------------------------ Spectroscopic observations were done at the Gemini-North observatory approximately 5 hours after the GRB. Using GMOS, a spectrum covering wavelengths from 4000 to 8100 angstroms was obtained. The spectrum shows a featureless continuum except for the presence of a weak double line, interpreted as Mg II (2796,2803). The redshift is z=1.036 under this assumption. Since no other features are seen, it suggests the redshift is between 1.036 < z < 2.7 (GCN 12202)." GRB 110721A 22:05:00 -36:25:00 7.51 -53.72 Grus 2011/07/21 04:47:43.75 Fermi 0 "This burst had a FRED light curve with duration about 24 seconds long. The spectrum was best fit by a Band Function with alpha = -0.94 +/- 0.02, beta = -1.77 +/- 0.02 and Epeak = 372.50 +26.50/-23.60 keV. This burst was 40 degrees from the LAT boresight at the time of the trigger, and the satellite automatically repointed to put the source closer to the LAT field center. The LAT then observed the source for the following 2.5 hours, subject to Earth limb constraint. The LAT showed a significant increase in emission that correlated in both space and time with the GBM data. More than 20 photons were seen to have energies in excess of 100 MeV, with the highest energy photon recorded being at 1.7 GeV. The light curve in the LAT had a similar FRED shape to that in the GBM, though the duration was only about 16 seconds long (GCN 12188)." score GRB 110719A 01:38:19.40 34:35:10.2 133.78 -27.3 Triangulum 2011/07/19 06:09:11 Swift None has been reported. This burst lasted about 50 seconds. Its light curve consisted of a single noisy FRED peak. The satellite slewed immediately to the burst and began observations with the XRT 111 seconds after the trigger. A bright, uncatalogued x-ray source was found. No optical candidate was seen in the initial UVOT data. GRB 110715A 15:50:44.09 -46:15:06.5 332.29 6.15 Norma 2011/07/15 13:13:50 Swift Counterpart seen at m = 17.34 z=0.82 "This GRB had a double-peaked structure and a duration about 15 seconds long. Swift slewed immediately to the burst and started observing with the XRT 91 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The contemporaneous imagery from the UVOT, begun 99 seconds post-trigger, showed an optical afterglow candidate with a magnitude of 17.34. Additional observations with the UVOT confirmed detection of this OC and provide the following magnitudes (GCN 12162): Filter T_start(s) T_stop(s) Exp(s) Mag white 100 249 147 17.37 +/- 0.06 u 312 501 187 17.86 +/- 0.09 b 3734 3857 121 19.5 +/- 0.3 white 3960 4160 197 19.92 +/- 0.16 uvw2 4166 4366 197 >20.1 v 4371 4571 197 19.3 +/- 0.3 uvm2 4576 6211 393 >20.3 uvw1 4781 6280 259 >20.1 u 4986 5186 197 20.1 +/- 0.4 b 5192 5391 197 19.9 +/- 0.2 Observations from the VLT/X-shooter taken about 12.3 hours after the GRB showed the OC at R = 18.45. A ten minute spectroscopic exposure was made, and these resulting spectrum showed Ca II and Ca I absorption, both at z = 0.82. (GCN 12164) In addition to confirmation of this source by several other ground-based optical telescopes, sub-millimeter observations were made of the target 1.42 days after the GRB. Using the LABCOA/APEX instrument in Chajnantor, Chile, observers report a detection at 11.0+/-2.3 mJy (GCN 12168)" GRB 110709B 10:58:37.24 -23:27:17.9 271.98 32.55 Crater 2011/07/09 21:32:39 Swift none has been reported. "Swift slewed immediately to this burst, which had overlapping peaks and a duration of about 60 seconds. The XRT began observing the field 80.5 seconds after the trigger, finding a bright, uncatalogued x-ray source within the BAT error circle. No optical candidate was seen in contemporaneous UVOT observations. However, 11 minutes after the first trigger, the BAT triggered on this source again. Since the source was already being observed by Swift’s three instruments, no slew was necessary. The light curve showed a broad hump beginning around T-100s, followed by several overlapping peaks, just as in the first light curve.These had a duration about 40 seconds long. Another peak was seen around T+200s, giving a total duration for this second peak of about 300 seconds - this after the initial burst 11 minutes before. Ground-based observations of this field were made using the Geminia-South telescope in Chile. In poor seeing and high airmass, a stack of 5 180 second r-band exposures revealed a faint source within the XRT error circle. No information was given on the brightness of this source in the circular (GCN 12128). Additional ground observations made using the GROND Multi-band Imager on the 2.2 meter MPI/ESO telescope at La Silla revealed a possible afterglow distinct from that reported earlier in GCN 12128. The images, taken 62 minutes after the trigger, showed r’ = 22.15 +/- 0.15 for this new source. It was not possible to determine if the source was fading (GCN 12129). Further analysis of the Gemini images were able to pull out this same source, with r = 22.18 +/- 0.12 (GCN 12132). Followup observations taken four days later with the Gemini/GMOS again detected these same objects and found no evidence that either had faded (GCN 12155)." GRB 110709A 15:55:33.86 40:55:28 65.23 49.96 Hercules 2011/07/09 15:24:29 Swift none has been reported. "Swift slewed immediately to this burst, which had a duration of 50 seconds and 8 peaks of roughly equal brightness in its light curve. The XRT began observing the field 66 seconds after the trigger, finding a bright, uncatalogued x-ray source within the BAT error circle. Contemporaneous UVOT observations failed to show any optical counterpart to the GRB. The Fermi/GBM also triggered on this event. The burst was 54 degrees from the LAT boresight, so the spacecraft executed an automatic maneuver to place the target closer to the boresight. The position was then observed for the following 2.5 hours, excluding limitations imposed by Earlth’s limb. The GBM light curve showed several peaks and a total duration (T90) of about 44 seconds (GCN 12133)." GRB 110705A 10:42:00 24:00:00 211.75 60.72 Leo Minor 2011/07/05 03:37:11.94 Fermi 0 This was a short burst, with the GBM light curve showing a single spike of 0.2 second duration. The spectrum was fit by a Band function with alpha = -0.17 +/- 0.07, beta = -3.0 +0.2/-0.4 and Epeak = 1010 +90/-80 keV. The burst was also detected by INTEGRAL, Konus-Wind and Suzaku, as well as satellites of the IPN. GRB 110625A 19:06:55.65 06:45:13.9 40.7 -0.35 Aquila 2011/06/25 21:08:28 Swift none has been reported. The BAT light curve for this burst contained several prominent peaks. It had a duration of about 60 seconds. The satellite slewed immediately to this burst and XRT began observations 140 seconds after the trigger. A bright, uncatalogued, fading x-ray source was found. No afterglow candidate was detected in contemporaneous UVOT data. GRB 110618A 11:47:14 -71:41:16 297.88 -9.45 Musca 2011/06/18 08:47:25 Konus-Wind 0 "http://www.ioffe.ru/LEA/GRBs/GRB110618_T31673/ " "This burst was reported by the IPN, having been detected by Farmi/GBM, INTEGRAL/SPI-ACS, Konus-Wind, MESSENGER, Mars Odyssey and Swift (outside its coded field of view). The position reported here was determined through triangulation using these various missions. The Konus-Wind light curve is reported to have been unusual in the gradualness of its onset. The spectrum began quite hard and then softened over the 250 second duration of the burst (GCN 12078). Optical imaging of the IPN error box (approximately the inner 6%) using the 1.3 meter SMARTS telescope at CTIO found no new optical sources (GCN 12081)." GRB 110610A 20:32:42.97 74:49:31.2 108.36 19.9 Draco 2011/06/10 15:21:32 Swift none has been reported. "Swift slewed immediately to this burst. The light curve contained several peaks and it lasted about 60 seconds. The XRT began observing 72 seconds after the trigger, finding a bright, uncatalogued X-ray source. UVOT products were not immediately available because of the presence of a bright star in the field of view. Observations from the MASTER II robotic telescope in Tunka, Russia did not detect any optical afterglow to a magnitude around 15.0. The observations were begun 55 seconds after the trigger (GCN 12066). This burst was also detected by the Fermi/GBM. It’s duration in that instrument was 40 seconds (T90). The spectrum was best fit by a power law with exponential cutoff. The power law index was -0.97+/-14.0, Epeak = 189.9+/-14.0 keV (GCN 12073)." GRB 110604A 18:04:00.7 18:28:19.2 44.68 18.54 Hercules 2011/06/04 14:49:55.666 Konus-Wind 0 http://www.ioffe.ru/LEA/GRBs/GRB110604_T53385/ This burst was detected by Konus-Wind and also Swift/BAT, MESSENGER/GRNS, Suzaku/WAM and INTEGRAL/SPI-ACS. It had a duration of 30 seconds with 4 separate peaks occurring during that time. Triangulation using all these missions gave a location consistent with the reported BAT RA and DEC. No further BAT data products were available because of the low coding level. GRB 110530A 18:48:10 61:55:54 91.91 24.1 Draco 2011/05/30 15:31:02 Swift Afterglow seen with Rc=18.84 "This burst had a single peak lasting about 20 seconds. The satellite was not able to slew to the field for 11 minutes because of an observing constraint. As a result, the XRT was did not begin imaging the field until 434 seconds after the trigger, finding an uncatalogued x-ray source within the BAT error circle. The UVOT started a 150 second long finder chart exposure starting 437 seconds after the trigger. An optical afterglow candidate was found in these initial images with unfiltered magnitude m~20.13. Ground-based images were taken at the MITSuME 50 cm telescope at Akeno Observatory in Yamanashi, Japan. These images started about two minutes after the BAT trigger and showed a faint object within the XRT error circle with Rc=18.84+/-0.65 (GCN 12048). Additional observations from the same telescope taken at T+11 minutes showed the OC in Ic as well as Rc and showed further that the object had fallen to Rc=19.8+/-0.2. Images taken using the MASTER II robotic telescope in Tunka, Russia began 73 seconds after the trigger. No OC was detected to R ~15.2. However, the OC was detected in later images at R~19.5+/-0.5 (polarized, GCN 12050). The fading behavior of the source was confirmed by observations from Terskol Observatory, Russia (GCN 12052) and by additional Swift/UVOT observations (GCN 12057)." GRB 110529A 07:53:19 67:54:36 147.88 30.78 Camelopardalis 2011/05/29 00:48:42.87 Fermi 0 "This burst had two short bright peaks. The total duration for the GRB was 0.41 seconds. The spectrum was fit using a Band function with alpha = -0.88+/-0.06, beta = -2.05+/-0.15 and Epeak = 1161+/-265 keV. This burst was also seen in the LAT (GCN 12044) and by the Konus-Wind Satellite, which detected emission up to about 5 MeV (GCN 12045). " score GRB 110521A 08:00:31.90 45:49:35.7 173.67 30.74 Lynx 2011/05/21 15:51:31 Swift none has been reported. "This burst lasted about 20 seconds and consisted of several pulses. XRT starting observing the field 98 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. No optical candidate was seen by the UVOT in a set of corresponding observations. No optical counterpart has been reported from ground-based observers." GRB 110520A 08:57:21.78 56:25:38.5 160.65 39.56 Ursa Major 2011/05/20 20:28:48 Swift none has been reported. "This burst had a FRED like shape with a duration of about 30 seconds. Swift slewed immediately to the burst. XRT began observing the field 100 seconds after that trigger, finding a fading, uncatalogued x-ray source within the BAT error circle. The UVOT did not find any optical candidate in its initial views of the field. No afterglow detections have been reported from ground-based observers, only upper limits." GRB 110519A 17:26:33.0 -23:25:32.2 2.36 6.56 Ophiuchus 2011/05/19 02:12:16 Swift none has been reported. "This burst had a FRED pulse with a duration of about 35 seconds. Swift could not slew to the burst due to a Moon constraint. The constraint will be in effect until May 20 at 23:19 UT. While the burst was within 10 degrees of the Galactic center, this was likely to be a cosmological burst based upon the strength of its emission above 100 keV. The burst light curve seen by Konus-Wind had two major pulses lasting a combined ~35 seconds. The first pulse consisted of many minor peaks. The spectrum of the burst was fit by a Band function with alpha = -1.29 +0.08/-0.07, beta = -2.30 +0.15/-0.35 and Epeak = 229 +43/-35 keV (GCN 12019)." GRB 110518A 04:38:14 -34:11:43 235.91 -41.33 Eridanus 2011/05/18 20:38:14 IPN 0 This burst was detected by Konus-Wind, Swift (BAT), INTEGRAL SPI-ACS, RHESSI, Mars Odyssey (HEND) and MESSENGER (GRNS). Because the location of the burst was outside of the coded aperture on BAT no automated alert was sent by Swift. The burst light curve seen by Konus-Wind had two major pulses lasting a combined ~35 seconds. The first pulse consisted of many minor peaks. The spectrum of the burst was fit by a Band function with alpha = -1.29 +0.08/-0.07, beta = -2.30 +0.15/-0.35 and Epeak = 229 +43/-35 keV (GCN 12019). GRB 110503A 08:51:06.24 52:12:27.5 166.22 39.22 Ursa Major 2011/05/03 17:35:45 Swift Counterpart seen at R~19.3 z = 1.613 "The BAT light curve for this burst had a single peak lasting about ten seconds. Swift slewed immediately to the burst and started XRT observations 94 seconds after the trigger. A bright, uncatalogued x-ray source was seen within the BAT error circle. In corresponding observations from the UVOT an optical afterglow candidate was seen. It had a magnitude m~15.75. Observers at the Nordic Optical Telescope (NOT) on La Palma observed the GRB field about 3.7 hours after the trigger. The observations were made in UBVRI and the afterglow was detected in all filters. It had magnitudes of B ~ 19.7 and R ~ 19.3 (GCN 11994). A spectrum of the afterglow candidate was obtained using the 10.4 meter GTC on La Palma starting about 4 hours after the burst trigger. Absorption features of Si IV, Si II, C IV, Fe II, Al II, Al III, Zn II, Mg II and Mg I were seen at a common redshift of z = 1.613 (GCN 11993). This redshift was confirmed by observations made with the TNG telescope on La Palma (GCN 11997)." GRB 110428A 00:22:22.22 64:50:57.1 119.85 2.15 Cassiopeia 2011/04/28 09:18:30 Fermi "This burst was detected by both the Fermi GBM and LAT. The LAT detected emission all the way up to 3 GeV, and the LAT detection lasted for about 200 seconds. Automatic reporting of the burst was hindered because of the effects of powerful thunderstorms and tornadoes in Alabama (Huntsville). This field was observed by the Swift XRT as a Target Of Opportunity starting about 16 hours after the Fermi trigger. Two sources were found within the Fermi/LAT error circle. One is a known ROSAT x-ray source and is also seen in the Digitized Sky Survey. We list the coordinates of the second, uncatalogued source. See circular GCN 11984 for the coordinates of the other source and for further information about the XRT observations. In additional observations from Swift/XRT taken approximately two days after the trigger, the first source (seen by ROSAT and DSS) was still detected at the same flux as the initial observations. The second source was no longer seen, suggesting that it was the x-ray afterglow of the GRB (GCN 11989)." GRB 110426A 14:44:24 11:08:24 7.36 59.02 Bootes 2011/04/26 15:08:36 MAXI/GSC 0 "This burst was detected by MAXI/GSC aboard the International Space Station. The burst lasted about 18 seconds. The identification as a GRB was based upon the location and hard spectrum of the source. This field was observed twice by Swift/XRT. The first observation took place two hours after the MAXi detection. Four sources were seen within the MAXI error box. One was a known Digitized Sky Survey source and the other three were of low significance. In the second observation, taken about three days after the trigger, the DSS source was still seen, with no change in its flux. Additional sources were also detected, but these were also of low significance. None of them corresponded to the marginal sources seen in the first set of observations. As such, it is not clear than any x-ray afterglow has been seen (GCN 11990)." GRB 110422A 07:28:13.92 75:06:27.7 139.71 28.5 Camelopardalis 2011/04/22 15:41:55 Swift Counterpart seen at R~18.3 z=1.77 "This burst lasted about 50 seconds. The light curve had a complex structure. The satellite was delayed by 12 minutes from slewing to the burst due to an observing constraint. When the XRT was able to begin observing the field, 814 seconds after the trigger, a bright, uncatalogued x-ray source was found. No optical candidate was found by the UVOT in corresponding exposures. Imaging from the 1.5 meter AZT-33IK telescope at Sayan Observatory near Mondy, Russia revealed an optical afterglow with R=18.3. The images were taken about 15 minutes after the GRB trigger (GCN 11958). In the succeeding hours several other observatories reported seeing the afterglow, and it was seen to fade from the earlier observations. Spectroscopic observations were made using the TNG telescope on La Palma, Canary Islands. In a 700 second exposure covering from 3600 to 8200 angstroms a strong absorption feature was detected at 4290 angstrom. This feature was interpreted to be the CIV doublet at 1549 with a redshift of z = 1.77 (GCN 11977). This redshift was confirmed with observations from the 10.4 meter GTC on La Palma. In a spectrum obtained 3.3 days post-burst, absorption from C IV, Al II, Al III, Fe II, Mg II and Mg I were all seen at a common redshift for z = 1.770 +.- 0.001 (GCN 11978)." GRB 110420B 21:20:12 -41:15:51 0.55 -44.84 Microscopium 2011/04/20 22:42:11 Swift none has been reported. "This was a very short burst, with the single spike lasting a mere 64 milliseconds. Swift was not able to slew to the burst because of an observing constraint, which was not lifted until 40 minutes after the trigger. Following the lifting of the observing constraint, the Swift XRT began observing the GRB field at T+43.3 minutes. In an exposure lasting ~3.3 hours, an X-ray afterglow candidate was found lying 2.95 arcminutes from the refined BAT position for the burst. No fading was apparent from these first observations (GCN 11947). This burst was also detected by the Fermi GBM. Its position and duration were consistent with the Swift values, and the GBM showed that the gamma-ray light curve had a fast rise and slow decay (GCN 11952)." GRB 110420A 00:08:39.27 -37:53:12.0 340.14 -75.98 Sculptor 2011/04/20 11:02:24 Swift Counterpart seen at v=18.20 "This burst had a single peak lasting about 20 seconds. Swift slewed immediately to the burst and started observing with the XRT 88 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the field, finding an afterglow candidate in the 150 second finder chart exposure begun 97 seconds after the trigger. The UVOT observed the field for several minutes following the trigger, with the OC detected in all filters as shown in the table below (GCN 11948): Filter T_start(s) T_stop(s) Exp(s) Mag ##################################################### wh (FC) 97 247 147 17.81 +/- 0.05 wh 761 781 19 18.10 +/- 0.17 u (FC) 309 559 246 17.46 +/- 0.07 u 712 732 19 17.96 +/- 0.36 v 811 831 19 18.20 +/- 0.67 b 737 757 19 18.04 +/- 0.28 uvw1 688 707 19 17.08 +/- 0.24 uvm2 663 683 19 17.73 +/- 0.41 uvw2 614 634 19 17.91 +/- 0.35 ##################################################### The OC was also detected from the GROND multi-band imager on the 2.2 meter MPI/ESO telescope at La Silla, Chile. The magnitude was r’ = 20.6 +/- 0.1 in an exposure taken 22.5 hours after the trigger (GCN 11954). " GRB 110414A 06:31:29.43 24:21:44.7 188.97 6.75 Gemini 2011/04/14 07:42:14 Swift none has been reported. "This burst lasted about 50 seconds. It had multiple peaks. The satellite slewed immediately to the burst, and the XRT began observing the field 142 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. No optical candidate was found in UVOT data that were taken starting 308 seconds after the trigger. Preliminary limiting magnitude is 18.0. Optical followup from the ground did not reveal any candidate afterglow." GRB 110412A 08:53:58 13:30:59 214.16 33.19 Cancer 2011/04/12 07:33:21 Swift None has been reported. "This burst lasted 30 seconds and had a single peaked light curve. Swift was not able to slew to the burst because of an observing constraint. The burst was also detected by Fermi/GBM (GCN 11926)." GRB 110411A 19:25:46.13 67:42:42.0 99.11 21.81 Draco 2011/04/11 19:34:11 Swift Optical afterglow detected at R=21+/-0.2 (unconfirmed) "This burst had a double-peaked light curve and a duration of about 120 seconds. The satellite slewed immediately to the burst and started observing with the XRT 126 seconds after the trigger. A bright and fading uncatalogued x-ray source was seen. No optical counterpart was seen in the contemporaneous UVOT data. Observations from the Xinglong TNT telescope were begun 81 seconds after the GRB. The images were in unfiltered and R-band. A new source was seen near the XRT error box in the 37 combined 60 second exposures taken in R. The magnitude was estimated to be R = 21+//-0.2 at T+38 minutes (GCN 11923). This source was not confirmed by followup observations from the MASTER telescope in Russia. However, the MASTER images have fainter limiting magnitudes than the Xinglong observations (GCN 11924)." GRB 110407A 12:23:59 15:43:04 272.35 76.93 Coma Berenices 2011/04/07 14:06:41 Swift Optical afterglow detected at r'=20.9+/-0.1. "Despite this being an image trigger, the BAT still showed a broad shallow peak lasting about 100 seconds. The top of the peak was at about T+20 seconds. Swift slewed immediately to this burst and started XRT observations 159 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. No optical afterglow candidate was identified in the corresponding 150 second white light exposure from the UVOT. Observations from the 1 meter telescope of Lulin Observatory begun 21 minutes after the trigger showed an object with r’ = 20.9+/-0.1 at T+1438 seconds and r’ = 22.7+/-0.3 at T+4758 seconds. This object is close to the x-ray position and is likely the optical afterglow of the GRB (GCN 11899). " GRB 110406A 01:09:21 35:48:32 127 -26.92 Andromeda 2011/04/06 03:44:10 Fermi 0 This burst had a single smooth peak lasting about 3 seconds. It was also detected by Konus-Wind (GCN 11893) and the IPN (GCN 11900). Because of the proximity of the GRB to the Sun, no followup observations will be possible from Swift. It is noted that the position of the GRB coincides with the position of the dwarf lenticular galaxy NGC 404, which is undergoing vigorous star formation (GCN 11909). GRB 110402A 13:09:36.54 61:15:10.3 119.05 55.74 Ursa Major 2011/04/02 00:12:57 Swift Optical afterglow detected at R=20.8+/-0.1. "This burst showed multiple spikes in its light curve. Swift slewed to the burst after a 9 minute delay and began observing with the XRT and UVOT. A fading, uncatalogued x-ray source was seen within the BAT error circle in XRT imaging started 544 seconds after the trigger. No optical counterpart was seen in the corresponding UVOT data. The burst duration was 40 seconds. Ground-based followup was done at the LIverpool telescope beginning 14.85 minutes after the trigger. A faint source was seen within the XRT error circle, with R=20.8+/-0.1 (T+28 min) and I=20.75+/-0.17 (T+33 min). It was not clear if the source was fading (GCN 11585). Additional observations made with the Nordic Optical Telescope at La Palma imaged the field in R staring 74 minutes after the trigger. They note that the object reported in GCN 11585 had faded to R=21.10+/-0.02 in their first exposure, and that in their third it had dropped to R=21.17+/-0.04. This fading behavior suggests that the object is the GRB afterglow (GCN 11859). " GRB 110401A 17:54:00 26:52:00 52.15 23.76 Hercules 2011/04/01 22:04:19.63 Fermi none has been reported. The light curve for this burst contained two strong pulses and lasted about 2 seconds. The spectrum for the burst was fit using a Band function with alpha = -0.66+/-0.15, beta = -2.36+/-0.53 and Epeak = 1194 +/- 406 keV. The burst was originally classified as “Below Horizonâ€� by the onboard flight software. GRB 110328A 16:44:49.89 57:35:00.0 86.71 39.44 Draco 2011/03/28 12:57:45 Swift R~22 z=0.35 "This was an image trigger. As a result there was no information on the light curve available in the initial data release. Swift slewed to the burst and started observing with the XRT after 1475 seconds. An uncatalogued, bright x-ray source was found within the BAT error circle. Not optical counterpart was seen in the UVOT images to a limiting magnitude of about 19.6. Approximately an hour later, at 13:40:41, the BAT triggered again on what seemed to be the same object. It was not clear if this object is a GRB of unprecedented longevity, or if this is a new galactic transient (GCN 11824). Ground-based observations from the Gemini-North telescope failed to find any optical transient to a limiting magnitude of R=22.2. The images were taken two hours after the first trigger in very poor conditions due to the presence of clouds (GCN 11825). Inspection of a survey field done as part of the Palomar Transient Factory (PTF) shows a faint object that closely coincides with the XRT position of the x-ray transient seen by Swift. The optical object has a magnitude around R~22 (with large uncertainties). Since these images were taken in 2009 and 2010, it seems unlikely that this object could be associated with a GRB at cosmic distances, and so these data suggest an origin within our galaxy (GCN 11827). A spectrum of the PTF object was obtained that showed the source to have a redshift z=0.35 based upon emission from Hbeta and OIII (4959, 5007). The high redshift argues against the object being caused by a galactic x-ray transient, though it is possible that a transient is in a chance alignment with the extragalactic object. If a GRB, this would be of an type not seen before (GCN 11833). The object was also detected in EVLA observations taken about a day after the burst. The observations were done at 4.94 GHz and 6.69 GHz (GCN 11836) This object was observed by HST on 4 April. The optical source reported above was barely resolved as a galaxy, with the EVLA and IR sources corresponding to the galaxy nucleus. This suggests that the object is not a GRB at all, but some sort of AGN, perhaps a mini-blazar that went into outburst as it disrupted and devoured a star that had strayed too close (GCN 11881). Data were also obtained using the Chandra X-ray Observatory that overlapped significantly with those from HST (starting about an hour before and continuing about an hour after). The source showed bright x-ray emission that varied by a factor of two during the observations (GCN 11886)." GRB 110328B 07:50:24 43:12:00 176.27 28.5 Lynx 2011/03/28 12:29:19.19 Fermi 0 This burst had a single pulse and a duration of about 120 seconds. The spectrum was fit by a power law with exponential cutoff. The power law index was -1.17+/-0.04 and the cutoff energy was Epeak=538+96/-70 keV. This source was also see in the LAT, though the typical energy cutoff had to be lowered from 100 MeV to 50 MeV for the object to be seen. The spectrum of the LAT data has a steeper slope than reported by the GBM, which suggests a break in the spectrum between the low and high energy regimes (GCN 11835). score GRB 110319B 21:44:17.8 -56:46:24 337.79 -45.67 Indus 2011/03/19 19:34:02 Fermi 0 "This burst triggered the Fermi/GBM during a Swift slew. An alert to the IPN prompted an examination of the BAT data taken during the slew, which revealed a strong source. The position of the object remained in the SwiftBAT filed of view from the time of the trigger until the end of the slew. The light curve had a duration of about 18 seconds, with a single FRED profile. Followup observations with the XRT begun about 7.5 hours after the trigger showed an x-ray source within the BAT error circle. It was not clear from these initial data if the source was fading or not (GCN 11814). Only faint upper limits were reported from ground-based observations. The GROND multi-band imager was used to observe the GRB field. No optical afterglow was seen to g’>23.1, nor was any object seen in any of the other filters (GCN 11815)." GRB 110319A 23:46:00.43 -66:00:40.1 313.15 -49.8 Tucana 2011/03/19 02:16:41 Swift Optical afterglow detected at b=19.51+/-0.21 http://grb.sonoma.edu/images/swift_bursts/GRB110319A.jpg "This burst lasted about 30 seconds and had a double-peaked light curve. Swift slewed immediately to the burst and began observing with the XRT 56 seconds after the trigger. A bright, fading uncatalogued x-ray source was found. No optical counterpart was seen in contemporaneous UVOT imaging. The limiting magnitude for the UVOT data was 19.6. However, upon further imaging an optical source was detected in the unfiltered images as well as those in b and u. The magnitudes were b= 19.51+/-0.21 at T+3719 second and u=18.13+/-0.13 at T+277 second. The object had faded from view in b (>20.63) at T+11317 second, and had u=19.76+/-0.18 at T+4950 second. It was not seen in any of the other filters of the UVOT. The fading suggests that this is the optical afterglow of the GRB (GCN 11812). " GRB 110318B 14:06:42.74 -51:34:43.8 314.66 9.57 Centaurus 2011/03/18 15:27:09 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110318B.jpg "This light curve for this burst contained two peaks and lasted about 10 seconds. The satellite slewed immediately to the burst and began observing with the XRT 73 seconds after the trigger. A fading, uncatalogued x-ray source was found within the BAT error circle. The UVOT failed to detect any optical afterglow candidate in near-simultaneous observations. The limiting magnitude for the optical was m > 19.6 (unfiltered - GCN 11801). No optical counterpart has been reported from the ground. Faint upper limits were reported by observers at the La Silla using the GROND multi-band imager on the ESO 2.2 meter telescope (GCN 11809): g' > 23.7 r' > 23.6 i' > 23.6 z' > 23.4 " GRB 110318A 22:33:10.0 -15:16:40.9 46.06 -55.8 Aquarius 2011/03/18 13:14:19 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110318A.jpg The light curve for this GRB lasted about 20 seconds. It had two main peaks. Because of a Sun observing constraint the satellite was not able to slew immediately to the burst. The constraint remains in effect until April 11. As a result, there will be no XRT or UVOT data for this burst until after that time. GRB 110315A 18:36:46.27 17:32:19.6 47.11 11.05 Hercules 2011/03/15 23:57:04 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110315.jpg "This burst lasted about 20 seconds, and its light curve contained several distinct peaks. The satellite slewed immediately to the burst, and the XRT started observing the field 105 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. No corresponding optical source was found in the initial UVOT data. The MASTER telescope in Kislovodsk, Russia began observations 89 seconds after the trigger. In the initial 20 second exposure, no optical counterpart was present to magnitude 17.3. Additional images, 25 total, were co-added to reach a limiting magnitude of 20.0. The mid-time for the co-added images was T+3240 seconds (GCN 11791). Additional ground-based observations were made from the RTT 1.5 meter telescope located at Bakirlitepe, TUBITAK National Observatory, Turkey. The observations were made approximately one hour after the burst. 21 observations, each of 300 second duration, were made in Rc. No optical counterpart for the GRB was seen. The limiting magnitude of the combined images was Rc > 23.6 (GCN 11796)." GRB 110312A 10:29:55.47 -05:15:45.4 251.02 42.9 Sextans 2011/03/12 17:55:37 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110312.jpg "This was an image trigger, and so there was no immediate information about the light curve. The satellite slewed to the burst and started XRT observations 159 seconds after the trigger. A bright, uncatalogued, fading source was found within the BAT error circle. No optical source was found in the initial UVOT imaging. No optical counterpart has been reported from the ground. The earliest reported observations were from the MITSuME telescope at Okayama Astrophysical Observatory, Japan. Their observations were begun 39 minutes after the trigger, and their observations revealed no source in three filters: g’ > 17.8, Rc > 18.0, Ic > 17.4 (GCN 11789). Deeper limits were obtained from the RTT 1.5 meter telescope (Rc > 23.5, GCN 11788) and the GROND multi-band imager (r’ > 24.1, GCN 11785) at T+2hrs and T+6hrs, respectively. " GRB 110305A 17:23:31.37 15:48:08.7 37.94 26.4 Hercules 2011/03/05 06:38:01 Swift Counterpart seen at r'=23.7 http://grb.sonoma.edu/images/swift_bursts/GRB110305.jpg "This burst lasted about ten seconds. It had a flat-topped light curve with a superimposed short spike. The XRT began observing the GRB field 109 seconds after the trigger, finding an uncatalogued x-ray source within the BAT error circle. The presence of bright stars in the field preventing UVOT finder chart observations from being immediately available. However, observations taken starting 113 seconds after the burst and continuing for over 8 hours in various filters did not reveal any optical counterpart for the burst (GCN 11779). Observers at the GROND multi-band imager at La Silla, Chile, were able to begin observing the field 2 minutes after the burst. A faint source was found, which decayed by 0.8mag over 60.5 minutes, suggesting that this was the GRB afterglow. The source had r’= 23.7 +/- 0.1 at 116.9 minutes after the burst trigger (GCN 11774). An infrared afterglow was reported from the REM 60 cm telescope at La Silla. Images taken 4.5 minutes after the trigger show an object with H=15.0+/-0.3, but about twenty minutes later the object is no longer visible, with limiting magnitude at H > 16.5 (GCN 11781)." GRB 110301A 15:17:24 15:17:24 21.22 54.14 Serpens 2011/03/01 05:08:43.07 Fermi 0 This burst lasted about five minutes. Its light curve consisted of a single pulse with internal structure. The GBM trigger caused an automatic repointing of Fermi to follow the burst, but because of an Earth constraint, the repoint maneuver was not completed until 40 minutes after the trigger. GRB 110223B 10:00:56.02 -68:18:05.6 288.18 -10.46 Carina 2011/02/23 21:25:48 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110223B.jpg "The light curve for this burst was double-peaked and lasted about five seconds. Swift slewed immediately to the burst and began UVOT observations 72 seconds after the trigger. A fading, uncatalogued x-ray source was seen. Corresponding UVOT images did not detect any optical afterglow candidate, though this could have been caused by confusion due to the large number of optical sources in the optical field, which saturated the satellite telemetry. Observers using the GROND multi-band imager with the 2.2 MPI/ESO telescope at La Silla, Chile reported the detection of a possible optical afterglow in data obtained 2.7 hours after the burst. The single object seen within the XRT error circle had a magnitude of r’=22.1+/-0.1. The magnitude was calibrated against the GROND zero-points. It was not clear of the source was fading over the course of the observations (GCN 11756). " GRB 110223A 23:03:24.85 87:33:27.6 121.71 24.95 Cepheus 2011/02/23 20:56:59 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110223A.jpg "This burst consisted of a single peak lasting about five seconds. The satellite slewed immediately to the burst, with the XRT beginning observations 89 seconds after the trigger. A bright, uncatalogued x-ray source was detected within the BAT error circle. No optical counterpart was seen in the corresponding UVOT images. The initial unfiltered images have a limiting magnitude around m = 18. Ground-based observations from the 2 meter Liverpool telescope began observing this source 2.8 minutes after the trigger. Images were made in ri and z filters. No optical source was seen within the XRT error circle to the following magnitudes: Mid time from Tot Exposure Filter Limiting Magnitude trigger (s) (s) ------------------------------------------------------------ 1920 780 r > 22.2 2320 720 i > 21.6 2620 720 z > 19 ------------------------------------------------------------ There was an uncatalogued source detected 3.4â€� from the x-ray position with magnitudes r = 21.6 +/- 0.1 and i = 20.9 +/- 0.1. The source did not fade over the course of these observations (GCN 11762)." GRB 110213B 02:47:01.41 01:08:46.3 172.14 -50.35 Cetus 2011/02/13 14:31:48 MAXI/GSC 0 z=1.083 "The GSC instrument on the MAXI scientific payload on the International Space Station triggered on this object. Both its location and its spectral hardness ratio suggested that the object is a gamma-ray burst. Emission was detected for only part of the transit response of the telescope, resulting in large uncertainties in the transient position along the scan direction. Followup observations using the Swift XRT were made at about 13 hours after the trigger. Three point sources were found within the MAXI error box. Two of the sources had likely associations with known objects, but the third, the brightest of the three, had no known associated object (GCN 11725). The Palomar 60 cm telescope imaged the field about 37 hours after the burst. An object near the XRT object was seen with R ~ 19.8, and no corresponding object is seen either in USNO-B1 catalog or the DSS (GCN 11732). Observers using the Gemini South telescope and Multi-Object Spectrograph obtained a spectrum of the candidate object covering from 3900 to 6700 angstrom. The object had a smooth continuum with a series of strong, narrow absorption lines. These are identified as Mg I, Mg II, Fe II and Fe II* at a common redshift of z = 1.083 (GCN 11736). " GRB 110213A 02:52:00 49:17:29 142.3 -8.99 Perseus 2011/02/13 05:17:29 Swift Optical afterglow detected at R~17.1. http://grb.sonoma.edu/images/swift_bursts/GRB110213A.jpg z=1.46 "Swift slewed immediately to this burst, which had a single-peaked light curve and lasted about 10 seconds. XRT began observing the field after 92 seconds, finding a bright, uncatalogued X-ray source within the BAT error circle. In contemporaneous UVOT observations, a optical candidate was also found. It’s magnitude (unfiltered) is estimated to be 16.31. Ground-based observations with the Palomar 60 inch telescope taken about two minutes after the burst trigger revealed an R~17.1 object within the field (GCN 11706). The ROTSE-IIIb telescope at McDonald Observatory also detected the OC; in observations begun 27 seconds after the trigger, it was seen at m=15.8. Many additional ground-based observers confirmed the OC. A spectrum was obtained 36 minutes after the trigger using the BOK 2.3 meter telescope and Boller and Chivens spectrograph. It covered from 4000 to 8300 angstrom. Absorption was seen from Mg II and Fe II at a common redshift of z=1.46 (GCN 11708)." GRB 110212A 04:36:13 43:42:09 159.89 -2.46 Perseus 2011/02/12 01:09:08 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110212.jpg "Moon constraint prevented Swift from slewing immediately to this burst. The BAT light curve had a multipeaked structure and a duration of about 10 seconds. XRT and UVOT observations were made about 46 hours after the trigger. No afterglow candidate was found within the BAT error circle at that time (GCN 11729). Ground-based observations in the minutes and hours after the trigger also failed to detect any optical afterglow. The earliest reported observations were from the ROTSE-IIIb telescope at McDonald Observatory in Texas. Upper limits of m~16.8 at about a dozen minutes after the burst. Earlier observations were hampered by the still twilight sky (GCN 11700). Also on target within the first minute after the burst was the TELMA robotic telescope at BOOTES-2 station, Malaga, Spain. Limits of R>~15 at 32 seconds were reported (GCN 11701). Fainter limits, though at a later time, were obtained at the SARA-N telescope on Kitt Peak, Arizona, USA. The observations started 58 minutes after the trigger. Limits of R > 20, J > 19 are reported (GCN 11702)." GRB 110210A 00:52:18 07:47:30 123.3 -55.08 Pisces 2011/02/10 09:52:41 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB110210.jpg This burst was an image trigger, and so the BAT light curve did not show any obvious peak. Swift slewed immediately to the burst and began observing with the XRT about 136 seconds after the trigger. A bright, uncatalogued x-ray source was detected. No optical counterpart was seen in near-contemporaneous UVOT observations. GRB 110208A 01:29:50.92 -20:35:34.0 178.3 -79.06 Cetus 2011/02/08 21:10:46 Swift Possible optical counterpart at i=21.8. http://grb.sonoma.edu/images/swift_bursts/GRB110208.jpg "This burst had a single-peak light curve with a duration of about 15 seconds. Swift slewed immediately to the burst. XRT observations started 80 seconds after the GRB trigger, showing an uncatalogued X-ray source within the BAT error circle. No fading behavior was immediately apparent. The UVOT also observed the field, but no optical counterpart was seen in the initial 150 second unfiltered exposure to a limiting magnitude of about 18. Subsequent analysis showed the limiting magnitudes to be between about 20 and 21.5 in the various UVOT filters for observations that continued out to T+ ~8 hours (GCN 11683) . Ground-based observations in r and i from the Magellan-Clay 6.5 meter telescope did not show any afterglow to a limit of the DSS. The observations were each 180 seconds long and began 3.35 hours after the GRB trigger (GCN 11676). Subsequent analysis of the images did find a faint object within a refined XRT error circle (see GCN 11678). The point source is at i~21.8 (GCN 11681)." GRB 110207A 00:50:09.5 -10:47:23.8 121.81 -73.66 Cetus 2011/02/07 11:17:19 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB110207.jpg "This burst had a complex multi-peaked structure. It lasted about 40 seconds. Because of a Moon constraint Swift could not slew to the burst. Two of the MASTER robotic telescopes were used to observe the field of this burst. They arrived on target 65 and 30 seconds, respectively, after the GRB trigger. No optical counterpart was found to limiting magnitudes near 13 to 14 in polarizing V filters. Additional images over the next ~30 minutes pushed the limits to below R=17 (GCN 11660)." GRB 110206A 06:09:20.14 -58:48:25.3 267.59 -28.31 Pictor 2011/02/06 18:08:05 INTEGRAL Optical counterpart seen with b = 21.00 "This burst had a duration of about 20 seconds. The Swift/XRT observed the field starting about 8 hours after the trigger and continuing for about two hours. An uncatalogued X-ray source was found the INTEGRAL error circle. The source was constant over the period of the observations (GCN 11657). The UVOT also observed the field, finding a source with b=21.00+/-0.37 and u = 20.56+/-0.24 (GCN 11662). The field was also observed from the La Silla 2.2 meter telescope and GROND imager. The data were obtained starting about 6.42 hours after the trigger, and an object with r’ =21.2+/-0.1 was seen. The object was also detected in the other six GROND filters. There was no variability seen in this object, so it is not clear that it is associated with the GRB (GCN 11665). GROND again imaged the field about 24.6 hours post burst. In 8 minutes of imaging in all seven filters, the source had dimmed by 1.2 magnitudes, to r’=22.4+/-0.1, which supports itsbeing the afterglow of the GRB (GCN 11669). Similar results were obtained using the ANDICAM on the CTIO 1.3 meter telescope. The object was seen in I, with I =20.6+/-01. Only upper limits were found for J>18.8. These observations were begun 6.8 hours after the trigger, but lasted only about half an hour, so no fading was seen. (GCN 11668)." GRB 110205A 10:58:31.12 67:31:31.2 138.06 46.15 Ursa Major 2011/02/05 02:02:41 Swift Optical counterpart seen with R ~ 15 http://grb.sonoma.edu/images/swift_bursts/GRB110205.jpg z=2.22 "This burst lasted an extraordinarily long time, more than 300 seconds. It had multiple peaks over that period. The XRT began observing the field 155 seconds after the trigger, finding a bright, uncatalogued X-ray source. The UVOT also detected this burst. The estimated magnitude of the afterglow was 18.71, unfiltered. Thee burst was also seen from the ground. Observers at the TAROT observatory in France began observations 91 seconds after the trigger, finding an R=16.7 object consistent with the Swift source (GCN 11630). The ROTSE-III telescope at McDonald Observatory in Texas, USA began observing the field 82 seconds after the trigger. A m=17.0 (unfiltered) object was found, and it was reported over the course of several observations to m~14.0 (GCN 11631). The object was also seen to become brighter in TAROT follow-up imaging, increasing to around R=15 (GCN 11632). It was reported to have a magnitude around R=16.06 at T+~15 minutes by observers at the Liverpool Telescope, though additional observations were halted because of poor weather (GCN 11633). The Swift UVOT also detected the flaring activity (GCN 11634). Spectroscopy using the Lick Observatory 3m Shane Telescope and KAST spectrograph (Mt. Hamilton, CA) was obtained starting about 2h 45m after the trigger. Absorption features of Ly-alpha, OI 1302 and CII 3980 at a common redshift of z~1.98. No features of CIV were seen, nor were FeII 2344,2374 or 2382 seen (GCN 11635). A spectrum was also obtained using the FAST spectrograph on the FLWO 1.5 meter telescope. The data were obtained about 4.5 hours after the trigger. While the same Ly-alpha line was seen as reported from Lick, the redshift was slighter larger, at z~2.22. Additional lines were seen at this same redshift: Si II, Si II*, C IV and Al II (GCN 11638). The redshift of z~2.22 was confirmed by observations from the NOT telescope at La Palma, Canary Islands (GCN 11640)." GRB 110201A 09:10:19.25 88:36:19.3 124.23 27.92 Ursa Minor 2011/02/01 09:35:08 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB110201.jpg "This burst lasted about 17 seconds. It had a multi-peaked light curve. The XRT began observing the field about 67 seconds after the trigger, finding a fading, uncatalogued X-ray source within the BAT error circle. UVOT imaged the field in U beginning 126 seconds after the exposure. No optical counterpart was seen. Analysis of the initial images placed limits of U>20 (GCN 11625). The afterglow of this burst was not detected by any ground-based telescopes." GRB 110128A 12:55:34.73 28:03:54.3 78.77 88.69 Coma Berenices 2011/01/28 01:44:32 Swift Counterpart seen at R~22.2 http://grb.sonoma.edu/images/swift_bursts/GRB110128.jpg z>=2.339 "The light curve for this burst shows a single weak peak lasting about 20 seconds. The XRT began observing the field 140 seconds after the trigger, finding a fading, uncatalogued x-ray source within the BAT error circle. No optical counterpart was found in the initial data from the UVOT taken at roughly the same time. Ground-based observations taken using the TAROT 0.25 meter robotic telescope at Calern Observatory, France, did not show any afterglow to R~16 to 17. The observations were made between starting about a minute after the trigger and continuing for another five minutes (GCN 11604). However, in images taken with the 2.5 meter NOT telescope at La Palma, Canary Islands about 1.22 hours after the burst, an object is seen with R ~22.2. The object is not present in SDSS images of the field (GCN 11605). Observations using the VLT/Xshooter starting at about 6.5 hours after the trigger produced a spectrum with broad Lyman-alpha absorption feature as well as absorption from OI, CII, SiIV, CIV, SiII and FeII. All these lines were at a redshift of z=2.339. There was another absorption feature in the spectrum that was thought to be CIV at redshift z=2.20 (GCN 11607). Additional spectra were obtained using the 4.2 meter WHT on La Palma. The observations started about 2.7 hours after the burst, with the spectra covering from 4500 angstroms to 9400 angstroms. The S/N of the afterglow was not high enough to confirm the VLT redshift, but redshifts of two field galaxies were measured: These were at z = 0.639, with [OII] 3727, Ca II H&K and Hbeta all seen. The galaxy is offset by ~35 kpc from the GRB line of sight. The second galaxy, z =0.109 from Halpha and [NII] was offset by ~50 kpc. Either of these galaxies might have produced absorption features in the spectra obtained of the afterglow (GCN 11608). This GRB was also seen in the Suzaku WAM instrument, with the x-ray light curve showing a complex, multipeaked structure. The WAM light curve lasted about 6.4 seconds (11609). " GRB 110125A 22:05:00 -46:12:00 351.45 -52.16 Grus 2011/01/25 21:27:28.39 Fermi 0 This burst had a single pulse lasting about 5 seconds. The spectrum was fit by a power law of index -1.93 +/- 0.05. GRB 110123A 17:40:00 28:02:00 52.27 27.08 Hercules 2011/01/23 19:17:45.03 Fermi 0 This burst had a single main peak with substructure. It lasted about 18 seconds. The spectrum was fit by a Band function with alpha = -0.64 +/- 0.03, beta = -1.96 +/- 0.05 and Epeak = 280 +/- 15 keV. GRB 110120A 04:06:24 -12:00:00 204.49 -41.98 Eridanus 2011/01/20 15:59:39.23 Fermi 0 "This burst had a 5 second peak followed by a longer, 40 second tail. The T90 duration was about 27 seconds. The spectrum could be fit by a power law with exponential cutoff. The power law index was -0.87 +/- 0.04, and the cutoff energy was Epeak = 1156 +/- 172 keV. This burst was also seen in the LAT. Emission was detected up to about 2 GeV, with the highest energies detected about 72 seconds after the trigger. The LAT emission lasted more than 100 seconds" score GRB 110119A 23:14:21.14 05:59:10.5 84.01 -49.41 Pisces 2011/01/19 22:20:58 Swift Counterpart seen with m = 16.52 http://grb.sonoma.edu/images/swift_bursts/GRB110119.jpg "This burst had a multipeaked structure and lasted about 95 seconds. The satellite slewed immediately to the burst, beginning XRT observations 58 seconds after the trigger. A bright uncatalogued x-ray source was found. The UVOT also observed the field. Initial observations taken for 150 seconds without a filter commenced 67 seconds post-burst. An optical counterpart with an estimated magnitude of 16.48 was seen. This burst was also detected by the Fermi/GBM (GCN 11592). Followup observations with the UVOT showed the object to have the following magnitudes (GCN 11587): Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 67 217 147 16.52 +- 0.03 u_FC 279 529 246 17.69 +- 0.09 u 279 529 246 17.69 +- 0.09 v 609 23078 1298 17.8 +- 0.7 b 535 29769 2006 16.5 +- 0.1 u 279 28857 1347 18.0 +- 0.4 w1 658 24777 990 >20.7 m2 5290 23984 1263 >21.0 w2 4880 18996 1165 >21.5 Ground-based observations using the 1.3 meter PARITEL on Mt. Hopkins, AZ, USA, also detected the optical counterpart in the NIR (GCN 11583): post burst t_mid (hr) exp.(hr) filt mag m_err 3.78 0.64 J 17.9 0.2 3.78 0.64 H 17.0 0.2 3.78 0.64 Ks 16.2 0.2 Observations with the 0.5 meter MITSuME telescope at the Okayama Astrophysical Observatory did not detect the candidate to faint magnitudes, about 19 in g’, Rc and Ic. The observations were made 11.8 hours after the trigger (GCN 11585)." GRB 110118A 00:09:29 -41:05:34 331.98 -73.58 Phoenix 2011/01/18 17:31:52 Swift GRB 110116A 13:39:44 55:09:37 108.83 60.63 Ursa Major 2011/01/16 12:04:25 Swift GRB 110112A 21:59:43.77 26:27:22.9 81.69 -22.35 Pegasus 2011/01/12 04:12:18 Swift Possible optical counterpart at R = 19.6. http://grb.sonoma.edu/images/swift_bursts/GRB110112A.jpg "This burst had a single-peak light curve lasting about 2 seconds. Swift slewed immediately to the burst, beginning observations with the XRT after about 76 seconds. An uncatalogued source was found within the BAT error circle. In a corresponding 150 second finder chart exposure with the UVOT no optical counterpart was seen. Ground-based optical followup from the Xinglong TNT telescope began about 6 hours after the trigger.16 images were made, each of 300 second duration in R band. Combining all images, a very faint source was detected within the x-ray error box. The magnitude of the source was estimated to be 19.6 +/- 0.3 (GCN 11554). The William Herschel Telescope began observing the field 15.5 hours after the trigger, detecting a faint and possibly extended source within the x-ray error circle. The magnitude was estimated as i~22, suggesting a possible fading of the source between these and the Xinglong observations, though the positions of the two objects are only marginally consistent (GCN 11559). Followup observations and analysis from the UVOT found no optical afterglow consistent with either the TNT or WHT objects (GCN 11560). " GRB 110107A 19:59:33.6 41:53:19 77.19 6.34 Cygnus 2011/01/07 21:15:51 Fermi This burst was detected by the Fermi GBM, but it was also caught in Swift BAT data during a Swift satellite slew: A strong source is seen in a mosaic of BAT images taken during the slew. The burst lasted about 100 seconds, starting at about T-70 seconds and continuing to about T+40 seconds. The BAT data ended at T+21 seconds. The burst contained multiple peaks, and the highest flux rate occurred near T0 (the time of the GBM trigger). GRB 110106B 08:56:37.267 47:00:10.49 172.91 40.45 Ursa Major 2011/01/06 21:26:17 Swift Optical counterpart seen with i ~ 22.5. http://grb.sonoma.edu/images/swift_bursts/GRB110106B.jpg z=0.618 "This burst showed several peaks in its light curve, lasting a total of about 30 seconds. There was a 3.8 minute delay before the satellite slewed an began observing with the XRT and UVOT. At about 327 seconds after the burst the XRT obtained an image of the field. An uncatalogued X-ray source was seen within the BAT error circle. The UVOT took a near-simultaneous image to the XRT, but in the initial 150 second finder chart image there is no obvious optical counterpart. The first ground-based followup observations were made using the Xinglong TNT telescope 9 minutes after the burst. No counterpart was seen to a limiting magnitude of R~20 out to around 14 minutes post burst (mean time of observations, GCN 11528). Observations from the Liverpool Telescope at around the same time put similar limits on the afterglow brightness (GCN 11537). The William Herschel Telescope began observing the field about 3 hours after the burst. The i-band observations showed a faint extended source, i~22.5. The data did not clearly show a point source on top of the extended, one, but this magnitude is marginally brighter that the SDSS magnitude, so it is possible that a contribution from the GRB afterglow is responsible (GCN 11534). The Gemini-North telescope observed the field about a day after the burst, obtaining a spectrum of the faint galaxy in the XRT error circle. The spectrum covered from 3900 to 8100 angstrom. Emission from [O II], H-beta and [O III] are all present at a common redshift of z =0.618 (GCN 11538). In addition, subtraction of the earlier WHT image from the Gemini-N image reveals a fading source, presumably the GRB afterglow (GCN 11540)." GRB 110106A 05:17:13.39 64:10:24.6 147.33 14.8 Camelopardalis 2011/01/06 15:25:16 Swift http://grb.sonoma.edu/images/swift_bursts/GRB110106A.jpg "This light curve lasted about 4 seconds. It had a double peaked structure. Swift slewed immediately to the burst and began observations withe XRT 106 seconds after the trigger. An uncatalogued x-ray source was found in the promptly available data. The UVOT imaged the field at approximately the same time, but in the initial 52 second finder chart exposure no optical counterpart was seen. Observations from the TNG 3.6 meter telescope in the Canary Islands showed a faint object within the XRT error circle. The obect had R~24.5 and was also detected in I. There is also a galaxy just outside the XRT error circle with R = 18.2. It was not clear whether any of these sources was variable in the initial set of observations, acquired about 4.4 hours after the trigger (GCN 11524). Refinements of the X-ray position (GCN 11526) placed the faint object well outside the XRT error circle, but it moved the error circle to include edge of the galaxy mentioned previously (GCN 11524). A spectrum of the galaxy taken at the TNG 5.6 hours after the trigger over the wavelength range 3800 to 8000 angstrom revealed emission features of H-alpha, [NII] 6583, [SII] 6730 and H-beta at a redshift z = 0.093. Also seen are C H&K in absorption at the same redshift. While this galaxy does overlap the XRT error circle, it is only the outer stellar light that is included. The center of the galaxy is well outside the error circle, 7.3 kpc in projection. This is a large distance for a long duration GRB, typically the type associated with young stellar populations (GCN 11530)." GRB 110102A 16:23:31.43 07:36:50.0 21.93 36.23 Hercules 2011/01/02 18:52:25 Swift Counterpart seen at m = 17.93 http://grb.sonoma.edu/images/swift_bursts/GRB110102.jpg "This burst had a weak precursor at T0, and then a bright FRED-like pulse 135 seconds later. The total duration of the burst was about 170 seconds. The XRT began observing the GRB field 149 seconds after the trigger, finding a bright, uncatalogued x-ray source. A contemporaneous 150 second finding chart exposure with the UVOT also revealed an afterglow candidate at m=17.93. Ground-based optical observations were completed using the 50 cm MITSuME telescope at Okayama Astrophysical Observatory. The observations were done in g’, Rc and Ic about 1.3 hours after the burst trigger. The afterglow was seen in all three filters, with magnitudes as follows (GCN 11513): g‘ = 20.0 +/- 0.4 Rc = 19.6 +/- 0.3 Ic = 18.3 +/- 0.2 The burst was also seen by the Fermi GBM. The Fermi light curve started around T0-123 second, and the total duration was about 254 seconds (T90). The GBM saw several peaks for this GRB, unlike the two seen with the Swift BAT (GCN 11512)." GRB 101225A 00:00:47.47 44:36:01.0 113.52 -17.34 Andromeda 2010/12/25 18:37:45 Swift Optical counterpart seen with R = 22.1 http://grb.sonoma.edu/images/swift_bursts/GRB101225.jpg "This was an image trigger, and so the BAT light curve does not show any significant structure in the initial data. The satellite slewed immediately to the burst, but due to the delay between the start of the image interval (the trigger time) and the onset of XRT observations is more than 23 minutes. Nonetheless, the XRT found a bright, uncatalogued x-ray source within the BAT error circle. Subsequent observations with the XRT showed that the source faded. It’s decay followed a power-law with index 1.108+/-0.011. In addition, the UVOT also detected the afterglow at quite faint magnitudes, below about 20 to 21 in the B and UV filters (GCN 11499). Analysis of the BAT data for the burst showed that it entered the BAT field of view at about T-80 seconds. This happened during a pre-planned slew of the satellite. The flux declined from this point, and then increased at ~T+600. Fluctuations of low significance continued out to about T+1300 seconds (GCN 11500). This object was observed by several ground-based optical telescopes. The earliest observations were obtained using the Nordic Optical Telescope (NOT) which detected an R=22.1 object about 1.5 hours after the trigger. In approximately four hours between their first and second epoch observations they report that the OC faded by about 0.5 mag in R, while remaining mostly constant in I (GCN 11495 and 11496). Additional observations at the William Herschel Telescope (WHT) had faded further in R by the next day. A spectrum obtained at WHT of the source from 5000 to 9300 Angstrom did not show any absorption or emission lines, nor any continuum breaks, suggesting a redshift z < 3.1 (GCN 11502). This featureless continuum was confirmed and extended blueward to 3175 Angstrom by MMT observations. The optical spectrum was fit by a power law with spectral index 0.4, bluer than is typical for a GRB afterglow (GCN 11507). A break in the optical light curve was seen in NOT data, with the fading rate having increased about five days after the trigger (GCN 11508)." GRB 101224A 19:03:42 45:42:55 76.11 17.05 Lyra 2010/12/24 05:27:13 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB101224.jpg "This burst had a single short spike, lasting only 0.5 seconds. Some later activity was also possible, but it was not certain. Swift slewed to the GRB site and started XRT observations 78 seconds after the trigger. No x-ray source was found in the initial analysis, nor was any optical source seen in contemporaneous UVOT observations. The BAT position is close to the galactic plane, so this source might be a new Galactic transient rather than a GRB. Subsequent inspection of the XRT data showed a faint source within the BAT error circle. However, the data did not allow any determination to be made about whether or not the source was fading (GCN 11485). Subsequent observations lasting more than two hours showed that the x-ray source did indeed fade: it was observed during the first orbit of the spacecraft, but was not detected any time afterward (GCN 11488). This burst was also detected by the Fermi/GBM (GCN 11489)." GRB 101219B 00:48:55.35 -34:33:59.5 306.92 -82.54 Sculptor 2010/12/19 16:27:53 Swift http://grb.sonoma.edu/images/swift_bursts/GRB101219B.jpg "This was a image trigger, so there was no BAT light curve. Subsequent analysis showed a broad peak that started 20 seconds after the trigger and ended 60 seconds after. However, a pre-planned slew of the satellite meant that the GRB field did not come into view until just before the trigger. It is possible that there were additional light curve features that were missed. Observations with the XRT began 146 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. In addition, a 150 second finder chart exposure from the UVOT revealed a candidate afterglow with m ~ 17.84. The GBM on Fermi also saw this burst. The GBM light curve has a single peak lasting 51 seconds (GCN 11477). From the ground, the GROND multi-band imager began observing the GRB field 8.1 hours after the trigger. The field was high in the sky at the time of the observations (airmass = 1.05). The afterglow candidate seen in the UVOT data was confirmed. Though it had faded significantly, it was still detected in all seven GROND bands: g' = 20.4 +/- 0.1 r' = 20.0 +/- 0.1 i' = 20.0 +/- 0.2 z' = 19.6 +/- 0.1 J = 19.2 +/- 0.1 H = 18.8 +/- 0.1 K = 18.6 +/- 0.1 Additional observations made about 2.5 hours later showed that the OC had faded by about 0.3 mag in r’ and J (GCN 11478)." GRB 101219A 04:58:20.49 -02:32:22.4 201.6 -26.19 Orion 2010/12/19 02:31:29 Swift none has been reported "This burst had a duration of only 0.3 seconds. swift slewed immediately to the GRB field and began observations with the XRT 61 seconds after the trigger. A fading, uncatalogued x-ray source was found within the BAT error circle. No optical afterglow candidate was detected in the initial UVOT data taken contemporaneously to the XRT data. Initial ground-based followup observations were obtained using the ROTSE-III robotic telescope did not find any afterglow to a limiting magnitude of m ~ 15.7 in images from 12 seconds after the trigger. Additional images raised the limit to m>17.2 in the first 90 seconds after the trigger (GCN 11462). Subsequent observations using larger aperture telescopes did not detect any afterglow, but Gemini-South images taken in i-band about 45 minutes after the trigger did show a faint extended object within the XRT field (GCN 11464). Additional imaging using the Magellan telescope in J-band revealed the same object, with J~21.6. The object is possibly the host-galaxy of the GRB, but no evidence of the afterglow is apparent (GCN11469). " GRB 101213A 16:05:15.29 21:53:49.7 37.16 45.87 Serpens 2010/12/13 10:49:23 Swift None has been reported "This was a very long burst, lasting about 100 seconds. The light curve had a FRED-like shape. Swift slewed immediately to the field and started XRT observations 106 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. Observations from the UVOT at roughly the same time did not detect an optical counterpart. Limits on the UVOT magnitude were m>21.0 for the first set of exposures (GCN 11451). The burst also triggered the Fermi GBM and INTEGRAL SPI-ACS. The GBM showed two overlapping FRED peaks with a duration of 45 seconds (GCN 11454). The burst also was detected by the Suzaku WAM instrument (GCN 11458)." GRB 101204A 11:10:11.6 -20:26:04 273.04 36.49 Crater 2010/12/04 23:53:29 Swift 0 This burst was a single burst with a slow rise time and duration of about 10 seconds. No XRT/UVOT data were available because the burst was detected in ground-based analysis of BAT data after the fact. In follow-up observations with the XRT/UVOT taken about 35 hours after the burst a source was found by both instruments within the BAT error circle. It was not clear if the source was fading. The UVOT source had a magnitude of v=20.28 (GCN 11442). Additional observations from the ground using the Vatican Advanced Technology Telescope (VATT) confirmed the presence of the source, but were also unable to determine if it was fading. The observations were done about a day and a half after the burst (GCN 11444). The GROND multiband imager also imaged this OC. The observations were done 2.2 days after the burst, and they showed that the OC had faded by about 0.6 magnitudes in the time since the VATT observations. Furthermore, their seven filters allowed them to make a spectral fit which showed a power-law shape to the spectral energy distribution. Therefore, it seems that this source is the afterglow of the GRB (GCN 11445). GRB 101201A 00:07:49 -16:11:46 77.94 -75.11 Cetus 2010/12/01 10:01:48 Swift 0 This burst was detected in Swift/BAT ground analysis. It was also detected by the Fermi/GBM (trigger 312890511). There was no prompt XRT/UVOT data obtained with Swift, but a target of opportunity request was made. The burst had a duration of about 79 seconds. It had 3 overlapping peaks, though the BAT only showed about 50 seconds of the middle one (Fermi/GBM light curve was much more complete). Observations with the GROND multiband imager at La Silla, Chile found a bright, uncatalogued object within the BAT error circle. The source was detected in all seven GROND bands. The r' magnitude was 19.67+/-0.01 in images taken 14.6 hours after the trigger. The source then faded by 0.3 magnitudes in the first 90 minutes of GROND observations. Detection in all seven GROND bands implies that the source is at a redshift z less than about 3, given the reddening in the direction of the source (GCN 11430). GRB 101129A 10:23:41 -17:38:42 260.07 32.66 Hydra 2010/11/29 15:39:31 Swift 0 http://grb.sonoma.edu/images/swift_bursts/GRB101219A.jpg This was an image burst. It's count rate was too low to trigger an automatic alert. The burst was also detected by the Fermi GBM. Follow-up observations were made with the XRT and UVOT about 11 hours after the burst. No source was found by either instrument. The burst duration was about 0.35 seconds and it had a very hard spectrum, with power law index ~0.8. GRB 101123A 08:45:32 05:33:47 221.42 27.85 Hydra 2010/11/23 22:51:34.97 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/GRB101213.jpg The burst was initiated by a weak pulse that was followed by three separate emission peaks. The total duration was about 105 seconds (T90). The spectrum was fit by a Band function with alpha = -0.75+/-0.01, beta = -2.14+/-0.03, Epaek = 476 +/- 11 keV. This burst was also observed by INTEGRAL, AGILE, Swift, Konus-Wind and other IPN spacecraft. GRB 101117B 11:32:00.33 -72:39:46.5 297.02 -10.71 Musca 2010/11/17 19:13:23 Swift Optical counterpart seen with m = 18.3 http://grb.sonoma.edu/images/swift_bursts/GRB101117B.jpg This burst was detected by Swift/BAT. It had two spikes and a total duration of about 6 seconds. Swift slewed immediately to the burst, and the XRT began observing the GRB field 77 seconds after the trigger. A fading, uncatalogued x-ray source was found within the BAT error circle. No optical counterpart was detected in the initial inspection of the UVOT, begun 82 seconds after the trigger. Limiting magnitude for an optical counterpart was m > 20.4. However, subsequent analysis of the UVOT data did show an uncatalogued source coincident with the XRT object. It had a magnitude of m ~18.2 (GCN 11412). In addition, subsequent observations with the XRT showed that the x-ray source was fading, indicating that it was, in fact, the GRB afterglow (GCN 11415). GRB 101114A 20:12:46.3 14:01:44.4 55.04 -10.92 Aquila 2010/11/14 00:32:50 Swift 0 "This burst was detected by ground-processing of the data, as the actual even trigger was terminated prematurely because of a slew maneuver to another source. The burst had a single FRED peak that started before the designated T0, peaked at T)+2 and ended after T0+10. The duration is therefore longer than 10 seconds, but the BAT data are not complete enough to give the entire duration. XRT data of the burst was obtained between about 20 hours and 25 hours after the burst. They show an uncatalogued x-ray source within the BAT error circle. There is weak evidence for fading in these data. This burst was also detected by Konus-Wind. It showed the same bright peak detected by the BAT, but also showed two weaker peaks preceding it. The first was at ~T0-100 seconds and the second at ~T0-50 seconds. Together with the main burst these suggest a duration longer than 110 seconds (GCN 11408). No optical counterpart was reported. Upper limits from the La Silla 2.2 meter MPI/ESO telescope and GROND multiband imager were fainter than 21.8 in g’ and i’>21.7 (see GCN circular 11409 for limits in other five filters)." GRB 101112A 19:28:54.87 39:21:11.1 72.11 10.2 Cygnus 2010/11/12 22:10:24 INTEGRAL 0 http://grb.sonoma.edu/images/INTEGRAL_Bursts/101112Alc.jpg "This burst lasted 10 seconds. It was detected by the IBAS instrument on INTEGRAL. A fading afterglow candidate was found using the Liverpool 2 meter robotic telescope. It had R=15.99+/-0.2 after 7.7 minutes and R=17.05+/-0.03 after 19.2 minutes (GCN 11397). The afterglow was also seen by the BOOTES-2/TELMA 0.6 meter robotic telescope in Malaga, Spain. These data show that R~18 for a mid-exposure time 156 seconds after the GRB trigger (GCN 11398). Additional ground-based optical telescopes also detected the afterglow of this GRB. This burst was observed by the Swift XRT, which found a fading x-ray source in observations made from ~1:42 hrs to ~5 hrs after the trigger (GCN 11399). The Fermi GBM also triggered on this burst. It measured a duration of about 9 seconds total, with a weak peak preceding the stronger, short trigger peak (GCN 11403). Konus-Wind also triggered o this burst, measuring a duration of ~15 seconds (GCN 11400). Observers using the EVLA radio telescope in New Mexico report a possible detection of this burst at 33.56 GHz. It had a flux density of 149 uJy about 3 hours after the GRB trigger (GCN 11404)." GRB 101030A 11:05:31.68 -16:22:41.2 269.28 39.47 Crater 2010/10/30 15:56:29 Swift Afterglow seen with g'=22.9 "This burst occurred during a preplanned slew of the Swift satellite. As a result, Swift did not trigger until the burst had been going for more than a minute. The light curve shows a bright peak that happened about 70 seconds before the trigger, then another outburst about 10 seconds before that had two overlapping peaks and lasted about 80 seconds. It is possible that Swift could have missed earlier emission from the burst, before T-100 seconds, due to this preplanned slew. The XRT began observing the GRB field 66 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. No object was seen in the initial UVOT images taken at roughly the same time. Subsequent analysis of the UVOT data put limits of m > 20.32 (unfiltered) in the first ~4 minutes after the trigger (GCN 11389) Imaging data was obtained using the GROND multi-band instrument on the 2.2 meter telescope at La Silla, Chile. These data were obtained 16.3 hours after the trigger, and an afterglow was seen in five of the seven GROND bands (GCN 11391): g' = 22.9 +- 0.3 r' = 22.4 +- 0.1 i' = 22.0 +- 0.1 z' = 22.1 +- 0.2 J = 21.7 +- 0.4 H > 21.2 K > 20.5 " GRB 101024A 04:26:01.54 -77:15:53.2 290.55 -34.13 Mensa 2010/10/24 11:39:29 Swift Afterglow seen with m = 19.38 http://grb.sonoma.edu/images/swift_bursts/GRB101024.jpg "This burst had four distinct peaks and a duration of about 23 seconds. The brightest of the peaks occurred at T+10 seconds. Swift slewed immediately to the burst and began observing with the XRT 77 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. In addition, UVOT data taken at nearly the same time revealed an afterglow candidate with m~19.38. The burst was also detected by Fermi/GBM, though they report three peaks rather than four over a similar duration (GCN 11378). Observers reported seeing this afterglow with the Zadko robotic telescope in Australia during the first five minutes after the trigger. Their data show that the afterglow was fading over the period during which they observed it (GCN 11380): R t_start t_stop 16.75 259 289 17.07 305 335 17.15 349 379 17.19 394 424" GRB 101023A 21:11:51.24 -65:23:15.84 328.89 -38.88 Pavo 2010/10/23 22:50:12 Swift Counterpart seen at r = 20.5 http://grb.sonoma.edu/images/swift_bursts/GRB101023.jpg "This burst lasted more than a minute and had a small initial pulse followed by a much larger FRED-like pulse at T+55 seconds. Swift slewed immediately to the burst, beginning XRT observations 85 seconds after the trigger. A bright, uncatalogued x-ray source was seen within the BAT error circle. The UVOT also imaged the field, but no OC was seen to m ~ 19.6 in the initial data analysis. Fermi’s GBM also triggered on the burst (GCN 11376). Ground-based observations taken from La Silla, Chile, using the 60 cm REM telescope did not detect any OC. These images were taken in H-band 37 minutes and 63 minutes after the trigger. Limiting magnitudes were H~14.8 and H~ 15.5 for the images, respectively (GCN 11364). Observations using Gemini-South/GMOS were taken starting about 1.8 hours after the trigger, with additional images collected about an hour later. A fading source was found with r~20.5 in the first set of images, and fading by ~0.38 magnitude by the second epoch (GCN11366). The afterglow was also detected using the GROND multiband imager in all seven bands. Data collected 1.2 hours after the burst showed the following magnitudes (GCN 11369): g' = 21.16 +/- 0.04 r' = 20.50 +/- 0.02 i' = 20.00 +/- 0.02 z' = 19.59 +/- 0.02 J = 19.08 +/- 0.04 H = 18.76 +/- 0.06 K = 17.64 +/- 0.06 The OC was also detected using the University of Tokyo 1 meter Atacama Telescope on Cerro Chajnantor, Chile. The JHK observations began about 3 hours after the burst, and the afterglow was detected in all three bands (GCN 11379): Band Mid-UT AB-Mag ---------------------------- Ks 02:53:05 19.40 +/- 0.10 H 03:07:41 20.28 +/- 0.27 J 03:24:36 19.92 +/- 0.14 ---------------------------- " GRB 101020A 12:38:15 23:09:39 265.26 85.04 Coma Berenices 2010/10/20 23:40:41 Swift none has been reported http://grb.sonoma.edu/images/swift_bursts/GRB101020.jpg Sun constraint prevented Swift from slewing to this burst. This was an image trigger, so the light curve showed no obvious structure. GRB 101017A 19:25:32.61 -35:08:42.5 3.46 -21.74 Sagittarius 2010/10/17 10:32:47 Swift Optical counterpart seen with m = 19.98 http://grb.sonoma.edu/images/swift_bursts/GRB101017.jpg This burst had multiple peaks within a FRED-like envelope. The total burst duration was about 40 seconds with additional weak emission detectable for as long as 100 seconds. The satellite slewed immediately to the burst. The XRT found a bright, fading uncatalogued source within the BAT error in observations beginning 81 seconds after the trigger. Contemporaneous UVOT images revealed an m = 19.98 (unfiltered) object within the XRT error circle. The source was not seen in subsequent imaging using various filters (GCN 11354), nor have ground-based observers reported seeing any optical counterpart. GRB 101014A 01:47:00 -51:04:00 282.92 -63.85 Eridanus 2010/10/14 04:11:52.62 Fermi 0 "The GBM light curve for this burst contained multiple pulses lasting a total of about 450 seconds (T90). The spectrum was best fit by a Band function with alpha = -1.27 +/-0.01, beta = -2.07 +/- 0.02 and Epeak = 181.40+5.66/-5.44 keV. The burst was seen by the LAT as well as the GBM (GCN 11349)." GRB 101011A 03:13:10.77 -65:58:54.5 283.3 -45.37 Horologium 2010/10/11 16:58:35 Swift Possible optical counterpart at m = =21.7 http://grb.sonoma.edu/images/swift_bursts/GRB101011.jpg "This burst had a total duration. It’s light curve consisted of at least 5 peaks. The satellite slewed immediately and began observing with the XRT 78 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found. No optical counterpart was seen in the initial UVOT observations taken around the same time. However, a marginal detection was made in subsequent, unfiltered imagery at around 1400 seconds past the trigger: a faint object, with m = 21.7+/-0.04 was seen. In still later images the source was not detected (GCN 11338). Ground-based observatories reported only faint upper limits." GRB 101008A 21:55:30.01 37:04:01.7 88.16 -13.66 Cygnus 2010/10/08 16:43:15 Swift Counterpart seen at Rc = 21.03 http://grb.sonoma.edu/images/swift_bursts/GRB101008.jpg "This burst lasted about 15 seconds and the light curve consisted of many peaks within an overall FRED shape. No immediate slew was possible because of an Earth limb constraint. The constraint was in effect until ~T+51 minutes. XRT observations were started about 53 minutes after the trigger. An uncatalogued x-ray source was seen within the BAT error circle. In contemporaneous UVOT observations, no OC was detected (GCN 11319). The 1 meter SAO, RAS in Russia was used to image the field between about 1.5 and 2.5 hours after the burst. The images revealed three sources not present in the DSS plates. The sources are all quite faint, with Rc magnitudes ranging from 20.84 to 21.03 (GCN 11324). Further imaging using the ESO 2.2 meter telescope and GROND multiband imager nearly 8 hours after the trigger also detected these sources, and they showed that one of them was fading, having dimmed 0.7 mag (GCN 11326). This burst was also detected by the Fermi GBM (GCN 11330)." GRB 100928A 14:52:09 -28:32:32.5 332.72 27.26 Hydra 2010/09/28 02:19:52 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100928.jpg This burst had a single peak lasting 6 seconds. A Sun observing constraint prevented the satellite from slewing and observing with the UVOT/XRT. GRB 100924A 00:02:41 07:00:53 102.11 -53.87 Pisces 2010/09/24 03:58:08 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100924.jpg This burst had a multi-peaked structure. It lasted about 90 seconds. Because of a moon constraint there was no slew to this burst. No XRT/UVOT data will be available at least until this constraint is lifted at 13:21 UT on 09/25/10. GRB 100917A 19:17:00.1 -17:07:12.1 20.26 -13.23 Sagittarius 2010/09/17 05:03:25 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100917.jpg "The BAT light curve consisted of a weak peak lasting about 4 seconds. Because of the Moon’s position, XRT/UVOT observations will not be possible until 19 September. As a result, no XRT/UVOT data will be available for this trigger. Detailed analysis of the light curve showed that it had a FRED-like shape, with a rise time of 5 seconds and a decay lasting ~ 30 seconds. The T90 measure of duration was 66+/-22 seconds." GRB 100916A 10:08:00 -59:23:00 283.44 -2.84 Carina 2010/09/16 18:41:12.49 Fermi 0 This burst was originally classified as Distance Particle trigger, but subsequent analysis showed that it was a GRB. The burst occurred close to the Earth’s limb, which caused the initial confusion. The GBM light curve showed a short ~0.5 second spike situated atop a broader, weaker bulge of emission lasting about 20 seconds. GRB 100915B 05:57:35 20:05:42 188.99 -2.17 Orion 2010/09/15 05:49:39 INTEGRAL 0 This burst lasted about 4 seconds. It was also seen by the Fermi GBM (trigger # 306222581). The GBM light curve had a single pulse lasting ~8 seconds (GCN 11284). GRB 100915A 21:02:46.66 65:40:22.9 102.17 12.52 Cepheus 2010/09/15 01:31:05 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100915.jpg "This was a BAT image trigger, so no light curve information was immediately available. The XRT began observing the GRB field 132 seconds after the trigger, finding a fading, uncatalogued x-ray source. No corresponding optical source was found in UVOT observations taken concurrently. Analysis of the BAT data revealed two broad peaks, the first beginning about 90 seconds before the trigger, peaking around T+5 sec and then continuing for an additional 85 seconds. The second peak began around T+110 seconds, peaked near T+170 seconds and ended at +190 seconds, making the total duration for the burst nearly 300 seconds. (GCN 11281)." GRB 100910A 15:24:24 -34:37:00 335.41 18.44 Lupus 2010/09/10 19:37:43.96 Fermi 0 This burst had 4 pulses. It’s total duration was about 15 seconds, and its spectrum was best fit by a Band function with alpha=-0.92+/-0.4, beta=-2.26+/-0.08 and Epeak = 143+/-7.0 keV. GRB 100909A 04:55:47.51 54:39:34.8 153.61 7.07 Camelopardalis 2010/09/09 09:04:00 INTEGRAL 0 http://grb.sonoma.edu/images/INTEGRAL_Bursts/100909Alc.jpg "This burst had a detection significance below that needed for an automated notice to be generated, so it was discovered in later processing of the data (the GCN notice went out nearly 80 minutes after the burst). The burst lasted about 60 seconds. The burst was observed by Swift as a Target of Opportunity about 3.2 hours after the INTEGRAL detection. A faint source was seen in the XRT data. No UVOT source was seen (GCN 11261). Subsequent observations taken about 7.2 hours after the INTEGRAL detection seemed to suggest that the source had faded, but the number of counts was too low to be certain (GCN 11268). Remarkably, ground-based observers did report seeing a possible afterglow, even with the delay in the reporting of the burst. The Faulkes-North Telescope was used to image the GRB field 1.6 hours after the trigger. Within the Swift-XRT error circle an uncatalogued object was found. This object was possibly fading. At T+2.07 hours it was at R=21.6+-0.2, and at T+5.05 it had dropped to R=22.1+/-0.2 (GCN 11265). Additional observations were done by observers using the Nordic Optical Telescope. The observations were carried out 19.4 hours after the burst, and using the same comparison star as the Faulkes observations derived a magnitude of R=23.2. (GCN 11269). The confirmation of the source and its fading indicates that this was indeed the GRB afterglow." GRB 100906A 01:54:50 55:36:49 131.86 -6.16 Perseus 2010/09/06 13:49:27 Swift Optical counterpart seen with R = 15.5. http://grb.sonoma.edu/images/swift_bursts/GRB100906.jpg z=1.727 "This was a long burst, lasting 130 seconds. Its light curve consisted of many bright peaks over that period. The satellite slewed and began observing with the XRT 80 seconds after the trigger, finding a bright, fading uncatalogued x-ray source within the BAT error circle. The UVOT also found a source in U images begun 146 seconds after the trigger. It had a magnitude estimated to be U = 14.90. This UVOT source is possibly associated with a bright flare seen in the x-ray light curve at T+120 seconds. The earliest reported ground-based observations of the burst are from the MASTER robotic telescope at the Krylov Observatory of Moscow State University, Russia. They report seeing a bright optical transient 43 seconds after the GRB trigger, though they give no magnitude information for their observations (GCN 11228). The Faulkes-North telescope observed the field about 3.5 minutes after the burst, finding an R=15.5 +.- 0.1 magnitude object (GCN 11229). A spectrum obtained using the Gemini-N/GMOS on Mauna Kea, HI approximately 40 minutes after the GRB showed absorption lines of CIV (1458, 1551), FeII (2344, 2374, 2383) and others, all at a common redshift of z = 1.727 (GCN 11230). The burst also triggered the Fermi/GBM, which showed several bright peaks, as for the BAT (GCN 11248)." GRB 100905A 02:06:07 14:55:54 148.49 -44.2 Aries 2010/09/05 15:08:14 Swift http://grb.sonoma.edu/images/swift_bursts/GRB100905.jpg "This burst had a single peak lasting about 6 seconds. An uncatalogued x-ray source was seen by the XRT in observations started 75 seconds after the trigger. No optical source was detected in the corresponding UVOT observations. The limiting magnitude for the UVOT observations was about 18. No optical counterpart was reported from any ground-based observatories." GRB 100904A 11:31:40 -16:12:32 276.54 42.54 Crater 2010/09/04 01:33:43 Swift http://grb.sonoma.edu/images/swift_bursts/GRB100904.jpg This burst had a two-peaked structure and lasted about 30 seconds. Because of a Sun constraint the telescope was not able to slew to observe with the XRT/UVOT. The proximity of the burst to the Sun prevents such observations until November 7, so there will not be any XRT/UVOT data for this burst. GRB 100902A 03:14:35 30:58:21 155.83 -22.6 Aries 2010/09/02 19:31:53 Swift http://grb.sonoma.edu/images/swift_bursts/GRB100902.jpg "This burst had an unusual light curve. It started with a small pulse or spike around the time of the trigger. This was followed about 150 seconds later by a brighter spike, and then another bright spike 50 seconds after that. The peak count rate actually occurred 210 seconds after the trigger! The XRT began observing the field 316 seconds after the BAT trigger, finding a bright and fading uncatalogued x-ray source. In an unfiltered exposure from the UVOT taken 325 seconds after the burst, no optical counterpart was seen to a limiting magnitude of m ~ 18. No optical counterpart was reported from any ground-based followup observations. " GRB 100901A 01:49:03.42 22:45:30.8 139.91 -38.21 Aries 2010/09/01 13:34:10 Swift Optical counterpart seen with m = 16 http://grb.sonoma.edu/images/swift_bursts/GRB100901.jpg z=1.408 "This burst lasted about 10 seconds. It’s light curve was composed of a single symmetric peak. The XRT started observing the field 161 seconds after the burst, finding an uncatalogued x-ray source within the BAT error circle. Observations from the UVOT were begun 147 seconds after the BAT trigger, and in the initial images a candidate afterglow was found with a magnitude of 19.67. The OC was seen by several observatories on the ground, the earliest reports coming from the MASTER robotic telescope of the Moscow State University’s Krylov Observatory. Unfiltered magnitudes at 101 seconds past the burst trigger were around m ~ 16 (GCN 11161). A spectrum obtained from the Gemini-North telescope. It showed many absorption systems, with the highest redshift one composed of Fe II, Al II and Si II all at z = 1.408 (GCN 11164). The afterglow from this GRB was also seen in the radio. The Westerbork Synthesis Radio Telescope in the Netherlands detected the afterglow at 4.9 GHz in observations done about 2.5 days after the trigger. In subsequent observations 5.5 days after the GRB trigger the radio source had brightened since the first set of observations (GCN 11256). The radio afterglow was also detected with the Extended VLA radio telescope in New Mexico, USA on Sept 6.47, approximately 5 days after the trigger. The observations were carried out in C-band (4 to 8 GHz), and detections were made at 4.5 and 7.9 GHz. Flux densities (brightnesses) were 331+/-30 Jy and 440+/-27 Jy in the two bands, respectively (GCN 11257)." GRB 100823A 01:22:49.03 05:50:06.4 137.05 -56.17 Pisces 2010/08/23 17:25:35 Swift Afterglow seen at K~19.6 http://grb.sonoma.edu/images/swift_bursts/GRB100823.jpg "This burst lasted 25 seconds. It had a FRED-like light curve. Observations with the XRT and UVOT began 69 and 77 seconds after the trigger, respectively. The XRT detected a bright, fading, uncatalogued x-ray source within the BAT error circle. No optical counterpart was found in the initial UVOT imaging. The limiting magnitude was m ~ 18. Observations done 7.2 hours after the burst with the William Herschel Telescope on La Palma showed a possible optical counterpart. However the z-band images showed two sources close to the XRT object; one was visible in archival DSS plates, and the other was not, but was offset from the XRT source by 6 arcseconds. It was not clear if they were the same. The fact that the WHT object was not seen in DSS plates could have been due to the different filters used for the two observations (GCN 11138). However, subsequent observations (5 hours after the first set) showed the same two objects at the same brightness within errors. Therefore it is likely the case that neither is related to the GRB (GCN 11142). Spectroscopy of one of the sources from the VLT/X-shooter revealed it to be an M-dwarf star (GCN 11143). Additional ground-based observations from the WHT approximately 8 hours after the burst revealed a faint object within the XRT error circle in addition to the two objects mentioned previously. The object had a K magnitude of 19.6. It was faintly visible in H, but was not seen in J or z, making it extremely red. The observers suggest that this object is the GRB afterglow (GCN 11145). Subsequent analysis of the early UVOT data showed that this source, originally misidentified as one of the two WHT sources mentioned earlier, did in fact fade slightly at early times (in unfiltered and u images). It then reached a steady brightness. This suggests that the third source from WHT was indeed the GRB afterglow (GCN 11148). " GRB 100816A 23:26:57.56 26:34:42.9 100.45 -32.58 Pegasus 2010/08/16 00:37:51 Swift Optical counterpart seen with m = 17.00, R = 20.5 http://grb.sonoma.edu/images/swift_bursts/GRB100816.jpg z = 0.8035 "This burst had a single symmetric peak. It lasted approximately 2 seconds. The satellite slewed immediately to the GRB field, starting XRT and UVOT observations at T+83 seconds and T+91 seconds, respectively. The XRT found a bright, uncatalogued x-ray source within the BAT error circle. The UVOT also detected the source, with preliminary unfiltered magnitude of 17.00. The UVOT afterglow was confirmed by observations with the TNG 3.5 meter telescope on La Palma. The observations began 2.8 hours after the burst and revealed an object with R~20.5 coinciding with the UVOT source (GCN 11104). The NOT/ALFOSC was used to image the field in R starting about 24 hours after the burst. The OC was detected at R = 23.0 +/- 0.1, as was the likely host galaxy at R = 21.65 +/- 0.05 (GCN 11120). The Liverpool Telescope imaged the field in R and I, finding that the OC had brightened to R = 19.75 +/- 0.2 at ~3 days post trigger. Contemporaneous images showed I = 18.32 +/- 0.04 at this time (GCN 11122). Imaging and GMOS spectroscopy from the Gemini North telescope confirmed the early fading behavior of the source (GCN 11109) and provided a redshift based upon O III 4995/5009 and Hbeta (4861) at a redshift of z ~ 0.245. The observers note that the redshift is tentative because their spectrum had quite low signal to noise (GCN 11116). Subsequent spectroscopy using the VLT/X-shooter arrived at a different redshift from the Gemini results. Based upon emission lines of Halpha, Hbeta, OII (3727), NII (6548/6583) and OII (5007) in emission. Absorption was seen from Ca II H&K. The system has two redshifts, corresponding to different sources: One is at z = 0.8034 and the other is at z = 0.8049. Reanalysis of the Gemini/GMOS spectrum by this same group identified faint absorption from Mg II (2797/2803) and FeII (2600), both at a redshift of z = 0.8035, consistent with the VLT redshifts for the emission lines, none of which were within the GMOS spectral window (GCN 11123). Observations from the GTC on La Palma confirmed the Mg II absorption at a redshift of z = 0.8049. The emission lines were not within the spectral window and so could not be confirmed (GCN 11125). " GRB 100814B 08:11:00 18:30:00 204.31 25.58 Cancer 2010/08/14 08:25:25.75 Fermi 0 The GBM showed a single pulse lasting about 6 seconds. The burst spectrum was best fit by a Band function with alpha = -0.62 +0.14/-0.11, beta = -2.49 +0.15/-0.20 and Epeak = 81.0 +6.2/-6.7 keV. GRB 100814A 01:29:55 -17:59:08 169.06 -77.26 Cetus 2010/08/14 03:50:11 Swift Optical counterpart seen with U = 16.8. http://grb.sonoma.edu/images/swift_bursts/GRB100814a.jpg z=1.44 "This GRB had three separate peaks over its 150 second long light curve. Both the XRT and the UVOT detected the afterglow in the prompt imaging done 87 seconds and 153 seconds after the BAT trigger, respectively. The UVOT magnitude for the afterglow was U = 16.8. A spectrum of this source was obtained at the Magellan Clay Telescope at Las Campanas. The spectrum, obtained an hour after the trigger, showed lines of All III, Fe II and Mg II, all at a redshift z = 1.44 (GCN 11089). The source was also observed at several other ground-based observatories. In fact, the afterglow was still visible in images taken 2.65 days after the burst using the 1 meter Lulin telescope. The magnitude at that time was R ~ 19.2 (GCN 11118). In addition, observations were undertaken at 345 GHz using LABOCA/APEX, but no afterglow was seen (GCN 11098). The burst was also seen by Fermi/GBM (GCN 11099)." GRB 100807A 03:41:12.01 67:40:18.2 138.02 9.92 Camelopardalis 2010/08/07 09:13:13 Swift Optical counterpart seen with R = 20.47 http://grb.sonoma.edu/images/swift_bursts/GRB100807.jpg "This burst had a single peak and lasted about 10 seconds. The XRT began observing the field 81 seconds after the trigger, finding a fading, uncatalogued x-ray source. The UVOT also imaged the field, but it found no optical counterpart. The Palomar 60 inch robotic telescope imaged the GRB field approximately 3 minutes after the trigger. They found an afterglow with the following fading behavior (GCN 11073): UT (mid-point) t_burst (min) Filter Magnitude --------------------------------------------------------------- 09:16:55 3.7 R 20.47 +/- 0.17 09:18:21 5.1 I 19.80 +/- 0.14 09:47:07 33.9 R 21.57 +/- 0.20 09:49:58 36.8 I 20.96 +/- 0.20 The Palomar 200 inch telescope also imaged the field, using the JH filters. The OC was detected as follows (GCN 11080): UT (mid-point) t_burst (min) Filter Magnitude --------------------------------------------------------------- 09:55 41 J 19.76 +/- 0.1 10:10 56 H 19.05 +/- 0.1 12:16 183 J 21.10 +/- 0.2 " GRB 100805A 19:59:30.52 52:37:40.3 86.57 11.79 Cygnus 2010/08/05 04:12:42 Swift Optical counterpart seen with m = 18.00 http://grb.sonoma.edu/images/swift_bursts/GRB100805.jpg "This burst lasted about 20 seconds and had a single peak. The satellite slewed immediately and began observations with the XRT/UVOT. In the XRT data a fading, uncatalogued x-ray source is seen. The UVOT data also showed the afterglow. These data were obtained at T+126 and T+129 seconds, respectively. The Palomar 60 inch telescope observed the field approximately 3 minutes after the trigger in r’, z’ and i’. An object with R [sic] = 17.3 was seen at the edge of the XRT error circle (GCN 11050). Subsequent monitoring showed that the source faded significantly, thus it was the GRB afterglow (GCN 11051). Additional observations at other observatories confirmed the existence of the GRB afterglow. The Liverpool telescope obtained the following magnitudes (GCN 11052): T-t0 (s) Exp. (s) Filter Mag ------------------------------------------------------- 400 10 r' 17.92 +- 0.07 421 10 r' 17.93 +- 0.07 726 10 r' 18.36 +- 0.10 3386 60 r' 19.79 +- 0.12 ------------------------------------------------ " GRB 100802A 00:09:52.15 47:45:16.2 115.73 -14.54 Andromeda 2010/08/02 05:45:36 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100802.jpg "This burst lasted about 30 seconds and had a single FRED-like light curve. Swift slewed immediately and began observing with the XRT 80 seconds after the BAT trigger. A bright, uncatalogued x-ray source was found, but no optical counterpart was found in the prompt UVOT data. However, in subsequent U imaging (beginning 301 seconds after the trigger) a candidate afterglow is seen with magnitude 19.56 (GCN 11032). Additional imaging showed that this source dimmed, with a tentative detection in the white filter (m = 21.86 +/- 0.48) at T+581, falling below the detection threshold after that (GCN 11038). Ground-based observations provided only upper limits on the brightness, with no OC found." GRB 100728B 02:56:13.46 00:16:51.9 176.26 -49.78 Cetus 2010/07/28 10:31:55 Swift Optical counterpart seen with m = 17.3 http://grb.sonoma.edu/images/swift_bursts/GRB100728b.jpg z = 2.106 "This burst had a single peak and lasted about 10 seconds. The satellite slewed immediately and began observing with the UVOT and XRT. In observations started 97 seconds after the burst the XRT found no x-ray source in the first 2.5 seconds of exposure. A hint of a source was seen in 80 seconds of WT data. In a reversal of the more typical case, the UVOT saw an optical counterpart where the XRT found nothing. The UVOT imaging began 100 seconds after the trigger, and the source had an unfiltered magnitude of 17.30. The Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, California, began observing the GRB field less than a minute after the trigger. An object with I = 18.7 +./- 0.3 was seen 95 seconds after the BAT trigger. Observations were also made with the nearby 1 meter Nickel Telescope, which also detected the afterglow. The OC was seen to fade over the course of the observations (GCN 11007,11010). The Nickel Telescope observations provided the following magnitudes (GCN 11025): tstart(s) exp(s) filt mag unc 397 60 R = 17.38 +/- 0.06 830 300 R = 18.33 +/- 0.05 1162 300 R = 18.53 +/- 0.06 1497 200 R = 18.71 +/- 0.07 1888 160 R = 18.88 +/- 0.09 2062 120 R = 18.80 +/- 0.09 2197 120 R = 18.99 +/- 0.11 This burst was also detected by four of the six PROMPT telescopes at CTIO, Chile. The observations started 45 seconds after the trigger and showed the following (GCN 11008, 11011): I = 4.62 +0.08 -0.07 R = 15.24 +0.07, -0.06 V = 15.78, +0.08, -0.07 B = 16.54 +0.21, -0.17 Observers also report detecting the optical counterpart using the GROND multi-band imager on the 2.2 meter telescope at La Silla in Chile (GCN 11013): J = 16.4 +- 0.1 H = 16.2 +- 0.1 K = 16.0 +- 0.1 A spectrum of this burst was obtained using the X-shooter on the ESO VLT beginning about 22 hours after the burst. The spectrum covers the spectral range from 300 nm to 2500 nm. Technical problems with the spectrograph rendered the signal to noise lower than usual. However, absorption from Lyman alpha and Mg II at a common redshift of z = 2.106 were detected (GCN 11317). " GRB 100728A 05:55:02.01 -15:15:19.1 220.66 -19.22 Lepus 2010/07/28 02:18:24 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100728a.jpg "This was a very long burst, lasting more than 200 seconds. The light curve had a multi-peaked structure. The XRT began observing the field 77 seconds after the trigger and found a bright, uncatalogued x-ray source within the BAT error circle. The UVOT saw no optical counterpart in the promptly available data. " GRB 100727A 10:16:42.57 -21:23:25.5 261.36 28.72 Hydra 2010/07/27 05:42:17 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100727.jpg "This burst had a single-peaked light curve and a duration of about 50 seconds. There was some possible activity that occurred about 175 seconds after the trigger. The XRT began observing the GRB field about 57 seconds after the trigger, finding a bright, uncatalogued x-ray source within the BAT error circle. No optical counterpart was seen in the prompt UVOT imagery. No optical counterparts have been reported from ground observations. The burst was also seen by the Fermi/GBM (GCN 11002)" GRB 100725A 19:20:08.33 76:57:23.0 108.65 24.78 Draco 2010/07/25 11:24:34 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100725a.jpg "This burst had a multi-peaked light curve. It lasted about 160 seconds. The satellite slewed immediately and began XRT observations 78 seconds after the trigger. A bright uncatalogued x-ray source was found within the BAT error circle. No optical counterpart was found in corresponding UVOT images taken around the same time. The limiting optical magnitude (unfiltered) is about 19.6 magnitude. Followup observations from the ground also failed to detect any optical counterpart." No optical counterpart was observed in ground-based observations. The Faulkes Telescope South placed limits R>~20 in a single 5 minute exposure obtained 1.7 hours after the trigger. Stacking six such exposures pushes the limit to R>21.3 (GCN 10982). Similar results and limits were obtained from the GROND multi-band imager: g’>22.8 at 16 hours post-trigger (GCN 10991)." GRB 100725B 11:05:55.57 -26:40:12.9 275.49 30.52 Hydra 2010/07/25 07:12:52 Swift 0 http://grb.sonoma.edu/images/swift_bursts/GRB100725b.jpg "This burst had multiple peaks and lasted more than 40 seconds. The XRT began observing the field 77 seconds after the BAT trigger, finding a bright, uncatalogued x-ray source within the BAT error circle. No afterglow was seen in corresponding UVOT data. The approximate optical magnitude limit is 18. No optical counterpart was observed in ground-based observations. The Faulkes Telescope South placed limits R>~20 in a single 5 minute exposure obtained 1.7 hours after the trigger. Stacking six such exposures pushes the limit to R>21.3 (GCN 10982). Similar results and limits were obtained from the GROND multi-band imager: g’>22.8 at 16 hours post-trigger (GCN 10991)." GRB 100724A 12:58:10.41 -11:06:09.7 305.6 51.73 Virgo 2010/07/24 00:42:19 Swift None has been reported http://grb.sonoma.edu/images/swift_bursts/GRB100724a.jpg z = 1.288 "This burst had a double-peaked light curve and a duration of 70 seconds. Swift slewed immediately to the burst and started XRT observations 89 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The UVOT also observed the field, but no optical counterpart was found in the 250 second U filter exposure that started 304 seconds after the trigger. Observers from the ground observed the field, and an afterglow was reported in images taken using the GROND multi-object imager on the La Silla 2.2 meter telescope (GCN 10969). In addition, the object was seen to fade over a ~half hour period between GROND observations by 1.3 magnitudes (GCN 10970). A spectrum obtained using the VLT/X-shooter 11 minutes after the burst showed absorption lines of F II 2344, 2383, 2586,2 600 , Mg II (2796, 2803) and Mg I 2852 all at a redshift of z = 1.288. The redshift calibration for these spectra was based on archival files, so this redshift is preliminary (GCN 10971). " GRB 100724B 08:00:09.6 76:44:24 137.63 30.27 Camelopardalis 2010/07/24 00:42:05.98 Fermi 0 "This burst had several pulses and lasted nearly 112 seconds. The source was tracked for five hours following the trigger, but the observations were delayed by ~45 minutes due to observing constraints. The spectrum was best-fit by a Band function with alpha = 0.84 +/- 0.01, beta = -1,84 +/- 0.01 and Epeak = 467.8 +15.3/-13.1 KeV. This burst was also detected by INTEGRAL and Konus-Wind (GCN 10981)." score GRB 100722A 15:55:00 -15:36:00 354.69 28.3 Libra 2010/07/22 02:18:37.24 Fermi 0 The light curve for this burst had several peaks. Its total duration was about 6.6 seconds. The satellite was able to track the GRB source for 5 hours after the burst, subject to Earth constraints. The GRB spectrum was best fit by a Band function with alpha=-1.01 -0.06/+0.07, beta = -3.54 -0.1/+0.08, Epeak = 68.1 -3.5/+3.4 keV. score GRB 100719A 07:29:016.6 -05:51:24.4 222.5 5.68 Monoceros 2010/07/19 03:30:57 Swift http://grb.sonoma.edu/images/swift_bursts/GRB100719.jpg This burst had a single peak with a duration of about 25 seconds. There is no XRT or UVOT data available because the location was too close to the Sun. This will remain the case until August 27, 2010. As a result, no XRT or UVOT observations will be made of this burst. GRB 100713A 17:00:48.46 28:23:41.6 49.85 35.47 Hercules 2010/07/13 14:36:06 INTEGRAL "This burst lasted 20 seconds. It was observed as a Target of Opportunity by the Swift XRT and UVOT. The XRT began its observations about 1h40m after the trigger. An uncatalogued x-ray source was found within the INTEGRAL error circle. No determination as to whether the source was fading could be made. The UVOT took a 150 second unfiltered exposure at about the same time, but no optical afterglow was seen (GCN 10952)." GRB 100707A 23:24:00 -06:34:00 73.68 -60.78 Aquarius 2010/07/07 00:46:38.99 Fermi This burst had a FRED light curve with a duration of 82 seconds. The spectrum was best fit by a power law with exponential cutoff: index = -0.91 +/- 0.02, Epeak = 283 +/- 7 keV. The Fermi/LAT also detected this burst. The object was 90 degrees off the LAT boresight, so non-standard analyses had to be used. The LAT showed a single sharp pulse with a gradual decay, similar to the GBM light curve. The total burst duration seen by the LAT was less than 30 seconds, but it’s possible this is due to the noisier data in the LAT, with the background swamping the late-time signal. score GRB 100704A 08:54:32 -24:12:56 249.34 13.19 Pyxis 2010/07/04 03:35:08 Swift http://grb.sonoma.edu/images/swift_bursts/grb100704.jpg GRB 100703A 00:38:05 -25:42:36 57.56 -86.69 Sculptor 2010/07/03 17:43:37.4 Fermi This burst was extremely short, lasting only 70 milliseconds. It was too low in significance to trigger automatic distribution and was discovered during interactive analysis of the data. GRB 100702A 16:22:48 -56:32:15 329.1 -4.82 Norma 2010/07/02 01:03:47 Swift http://grb.sonoma.edu/images/swift_bursts/grb100702.jpg This was a short burst, lasting only 0.3 seconds. The light curve showed a single peak. The satellite slewed immediately to the burst, with the XRT finding a bright, fading, uncatalogued x-ray source in images commencing 94 seconds after the trigger. The UVOT took a white light image starting 101 seconds after the trigger. No OC was found in the 150 second long exposure. GRB 100701B 03:02:00 -03:26:00 181.43 -50.84 Eridanus 2010/07/01 11:45:23.070 Fermi 0 This burst lasted about 27 seconds. Its light curve showed six or more main pulses. The spectrum for the burst was fit by a power law with exponential cutoff. The poser law index was -0.99 _/- 0.2, and the cutoff was Epeak = 1.85 +/-0.16 MeV. A Band function could also fit the spectrum. GRB 100701A 12:35:26 -34:15:39 299.17 28.49 Centaurus 2010/07/01 06:54:28 MAXI/GSC This was an x-ray flare detected by the MAXI/GSC instrument aboard the International Space Station. The flare lasted 30 seconds. Its position did not correspond to any known x-ray source. The source was not seen in scans carried out on previous or subsequent orbits of the station. GRB 100628A 15:03:53.52 -31:39:49.7 333.34 23.27 Lupus 2010/06/28 08:16:40 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100628.jpg "This was another very short burst. The light curve consisted of a single hard spike lasting only 0.1 second. Swift slewed immediately to this burst, beginning XRT observations 86 seconds after the trigger. No x-ray source was found in the promptly available data. The UVOT also observed the field, failing to find any counterpart to the GRB in the optical. However, analysis of additional data revealed the presence of an x-ray source within the BAT error circle. (GCN 10899) Ground-based observers found a faint source within the XRT error circle. The object was observed using both the Magellan telescope (GCN 1087, 10911) and the GROND multi-band imager (GCN10906, 10910). Neither set of observations found evidence of variability within this source." GRB 100625A 11:03:10.98 -39:05:18.3 280.98 19.13 Antlia 2010/06/25 18:32:28 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100625.jpg "This was a short burst, lasting only 0.4 seconds. The single peak showed some substructure. The satellite slewed immediately to the burst and began XRT observations 48.3 seconds after the trigger. A bright, uncatalogued x-ray source was found in the BAT error circle. No OC was found in 150 second unfiltered images taken by the UVOT starting 56 seconds after the trigger. Observers at the Gemini-South telescope in Chile reported possible detection of the afterglow in a 600 second r-band image taken approximately 12 hours after the burst. The object in question had r ~ 23. Poor seeing prevented determination of whether this object was the afterglow itself or the GRB host galaxy (GCN 10887). Subsequent observations 63 hours after the burst using GMOS found the same object, which had not faded since the first set of observations. This suggests that the object is the host galaxy (GCN 10905). The Gemini object was also observed using the Magellan telescope and PANIC IR detector at Las Campanas Observatory in Chile. The observations were done 39 hours after the burst and revealed a “mildly extendedâ€� object in J-band. (GCN 10897) This burst was also detected by the Fermi GBM (GCN 10912)." GRB 100621A 21:01:13.12 -51:06:22.5 347.44 -40.9 Indus 2010/06/21 03:03:32 Swift Counterpart seen at g'=22.7+/-0.4 http://grb.sonoma.edu/images/swift_bursts/grb100621.jpg z=0.542 "This burst lasted about 100 seconds. It had a triple-peaked light curve. Swift slewed immediately to the burst and started observations with the XRT and UVOT 76 and 84 seconds after the trigger, respectively. The XRT found a bright, uncatalogued object within the BAT error circle. No OC was found in the initial UVOT data. An OC was detected from the ground using the GROND multiband imager on the 2.2 meter ESA telescope at La Silla, Chile. The observations started 4 minutes after the GRB trigger and continued for 3 hours. Reported magnitudes for the GRB afterglow are as follows: g' = 22.7+-0.4 r' = 21.6+-0.1 i' = 20.5+-0.1 z' = 19.7+-0.1 J = 17.3+-0.1 H = 16.3+-0.1 K = 15.8+-0.1 These magnitudes are based on GROND zero-points and 2MASS field stars. They have not been corrected for Galactic extinction. This source is present in the DSS2 images, and there was no fading apparent over the course of these observations. Thus it is likely that the source is the GRB host galaxy. (GCN 10874). Additional ground-based imaging was carried out using the SIRIUS/IRSF 1.4 meter telescope in South Africa. The images, in JHK bands, began about an hour after the trigger and continued for nearly an hour. A new source was seen, and it brightened by ~ 1mag in all bands. Reported photometry is in the table (GCN 10881): --------------------------------------------------------------- Mid time from Total Exp. J-mag* H-mag* K-mag* trigger (min) (s) --------------------------------------------------------------- 61.41 300 16.56 15.22 14.18 67.61 300 16.24 14.63 13.84 73.84 300 15.27 13.78 12.63 80.14 300 15.07 13.57 12.40 86.36 300 14.93 13.45 12.23 92.56 300 14.90 13.45 12.32 98.81 300 14.93 13.47 12.34 105.0 300 15.04 13.55 12.36 --------------------------------------------------------------- *Typical error is ~ 0.1 mag A spectrum of this object was obtained using the X-shooter spectrograph and ESO VLT. The spectra covered from 3000 to 25,000 angstroms. Based upon emission from OII, H-beta and OIII a redshift of z = 0.542 was found. The wavelength solution was based on archival data, so there could be small offsets to the wavelengths (GCN 10876)." GRB 100619A 05:38:29.31 -27:00:19.2 231.06 -27.08 Lepus 2010/06/19 00:21:07 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100619.jpg "This was a very long burst, lasting about 120 seconds. It had two distinct peaks, separated by 90 seconds. The first peaked near the burst trigger, and the second stronger peak peaked at T+95 seconds. The satellite slewed immediately and began XRT observations 76 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found. No optical counterpart was found in UVOT data taken around the same time. The burst was also seen by the Fermi GBM. " GRB 100615A 11:48:49.25 -19:28:52.2 283.24 40.98 Crater 2010/06/15 01:59:03 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100615.jpg Swift slewed immediately to this burst, which showed 3 strong peaks in its light curve. The burst duration was about 60 seconds. The XRT began observing the field about 62 seconds after the trigger, finding a fading, uncatalogued x-ray source within the BAT error circle. In a 150 second UVOT image taken at about the same time no OC was detected. Upper limits (unfiltered) were m > 21.5 (GCN 10856). Only upper limits were reported by ground-based observers. GRB 100614A 17:33:59.81 49:14:05.1 75.98 32.55 Hercules 2010/06/14 21:38:26 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB100614.jpg "This was an image burst, so no light curve information was immediately available. However, subsequent analysis of the BAT data showed that the the GRB started about 10 seconds before the trigger. The emission rose for about sixty seconds, peaking around T+50, and then lasted until around T+275. The duration of the burst as measured by T90 was about 225 seconds (GCN 10852). Swift slewed immediately to this burst, starting XRT and UVOT observations about 130 seconds after the trigger. The XRT found a bright, fading, uncatalogued source within the BAT error circle. No afterglow was seen in the initial 250 second finder chart exposure from the UVOT, nor in subsequent imaging. Observers on the ground fared not better, reporting only upper limits to the afterglow brightness." GRB 100606A 23:22:30.37 -66:14:28.1 316.24 -48.53 Tucana 2010/06/06 19:12:41 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100606.jpg "Swift slewed immediately to this burst, which had multiple peaks and a duration of around 30 seconds. The XRT showed an uncatalogued x-ray source within the BAT error circle in observations starting 96 seconds after the trigger. In UVOT observations at around the same time no optical counterpart was seen. Subsequent analysis of UVOT data showed that not OC was detected to m > 21.08 in the first ~5 minutes after the trigger, nor to m > 21.70 in the first ~109 minutes after the trigger (GCN 10830). The Gemini South telescope imaged the GRB field approximately 11 hours after the burst using r, i and z filters. The total exposure time for each filter was 900 seconds. An extremely faint (r~25) extended object within the refined XRT error circle. The object is barely detected in the i and z bands. It is not obvious that the object has any contribution from the GRB afterglow, but it could be the host galaxy for the GRB (GCN 10831)." GRB 100528A 20:44:33.92 27:48:23.8 70.83 -9.22 Vulpecula 2010/05/28 01:48:05 SuperAGILE 0 "This burst had a duration of about 20 seconds. However, because the spinning operative mode of AGILE, the spacecraft was only able to provide a lower limit. The burst was also detected by the Fermi/GBM, and the duration (T90) from that set of data was 24.6 +/- 0.5 seconds (GCN 10811). The burst was also observed by the Swift XRT and UVOT. These observations started about 12 hours after the burst. They revealed a bright source within the AGILE error circle. Though the x-ray source was not observed to fade over the ~1.5 hours of pointed observations, it is not present in the ROSAT survey image of the field, nor was it present in an XMM data set that covers the field. The source was also seen in the UVOT, having an unfiltered magnitude of m = 20.96 +/- 0.13 (GCN 10813). The burst afterglow was also detected using the GROND multi-band imager on the 2.2 meter telescope at La Silla, in Chile. The observations were undertaken 54 hours after the burst, and the OC was seen in all filters, as shown below (GCN 10815): g' = 21.93+-0.08 r' = 21.56+-0.04 i' = 21.27+-0.05 z' = 21.36+-0.07 J = 20.49+-0.10 H = 20.25+-0.12 K = 20.46+-0.21 The OC was also detected by the Faulkes-North telescope in Hawaii. The observations were made about 1.5 days after the trigger, and the source was at r’=20.98+/-0.6 and i’=20.88+/-0.8 (GCN 10816)." GRB 100526B 00:02:56.52 -37:54:43.0 343.27 -75.17 Sculptor 2010/05/26 19:00:38 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100526b.jpg "This burst had several weak peaks and a total duration of about 30 seconds. There was no prompt slew of the telescope because of an observing constraint. As a result, no XRT or UVOT data were immediately available. Swift was able to slew and begin observing with the XRT and UVOT after a 55 minute delay. The XRT data showed an uncatalogued x-ray source within the BAT error circle. A 150 second long finder chart exposure from the UVOT did not detect any optical candidate to a limit of about m ~ 18 (GCN 10802)." GRB 100526A 15:23:04.57 25:37:56.4 39.18 56.13 Corona Borealis 2010/05/26 16:26:10 Swift Counterpart seen at K = 19.09, nothing in optical. http://grb.sonoma.edu/images/swift_bursts/grb100526a.jpg "Swift slewed immediately to this burst. Because it was an image trigger, no prompt light curve information was available. The XRT started observing the GRB field 146 seconds after the trigger. A bright, uncatalogued x-ray source was found. The UVOT also observed the field, but no optical counterpart was detected in the initial finder chart exposure. The limiting magnitude was m ~ 19.6. Subsequent analysis of the BAT light curve showed multiple overlapping peaks, with the first starting around T-70 and ending at ~T+115. The burst duration (T90) was 102 +/- 8 seconds (GCN 10801). Observers at the Nordic Optical Telescope (NOT) imaged the field in R and i bands between 6 and 7 hours after the GRB. No counterpart was found to R ~ 23.8 (GCN 10805). Images were also obtained from the Gemini-North telescope in H and K bands. A source was detected near the edge of the XRT error circle in both filters. The magnitudes were K = 19.09 +/- 0.13 (t_mid = 16.21 hours) H = 21.15 +/- 0.17 (t_mid = 16.75 hours) The observers not that its extreme red color would make this one of the most red GRBs yet detected, should this object turn out to be the GRB afterglow (GCN 10806)." GRB 100522A 00:27:56.79 09:24:06.6 113.27 -53.03 Pisces 2010/05/22 03:45:52 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/GRB100522a.jpg "This burst had two sets of double peaks. The first pair was near T0 and lasted about 5 seconds. The second pair of peaks was near T+30 and was fainter and softer. Swift slewed immediately to the burst and started observations with the XRT and UVOT. The XRT observations began about 65 seconds after the trigger. They showed a bright and fading uncatalogued x-ray source. No counterpart was found in the initial UVOT data to a limiting magnitude of m ~ 18.5. The UVOT observations began 73 seconds after the trigger. The Fermi/GBM also detected the burst. Their observations are consistent with those from the BAT in terms of both position and duration. They saw the same initial set of peaks lasting about 5 seconds, followed by a second set that began at about T+25 and lasted until about T+40 (GCN 10790). Observers from the ground were not able to detect the burst. The earliest observations came from the 0.6 meter TELMA robotic telescope at the BOOTES-2 astronomical station in Málaga, Spain. Their observations began about 10.5 minutes after the burst and failed to detect any counterpart to m = 15.5 (GCN 10785). The faintest limits were obtained using the GROND multi-band imager on the 2.2 meter ESO/MPI telescope at La Silla. These observations began 29.5 hours after the trigger and lasted for about an hour. No afterglow was found to the limits given below (GCN 10793): g' > 24.8, r' > 24.4, i' > 23.6, z' > 23.3, J > 21.7, H > 20.9, K > 20.6, " score GRB 100518A 20:19:09.43 -24:33:15.7 18.64 -29.46 Capricornus 2010/05/18 11:33:35 INTEGRAL Optical counterpart seen with r' = 23.8 "This was a FRED burst with a duration of about 30 seconds. It was initially detected by INTEGRAL, with observations being taken up by Swift about 2.6 hours after the INTEGRAL trigger. The Swift/XRT found an uncatalogued x-ray source within the INTEGRAL error circle (GCN 10775). Observations continued for approximately 2.5 hours, during which time the x-ray source was observed to fade according to a power-law decay with index 0.68+1.00/-0.96 (GCN 10780). The GRB afterglow was seen optically from the ground. The 2 meter Faulkes-North Telescope was used to detect the afterglow beginning 4.2 minutes after the burst and continuing for nearly four hours. The afterglow was detected in both R and i (no mention of detections in B and V, which were also employed), and its brightness decayed according to a power-law with index 0.7+/- 0.1, consistent with the decay seen in the x-ray band. The OC was initially detected with R = 19.4 +/- 0.1 at about 5 minutes after the INTEGRAL trigger (GCN 10779). The GROND multi-band imager also detected the OC. In images beginning about 22 hours after the burst, the afterglow was seen in three filters in the red and NIR part of the spectrum: g' > 25.3 r' = 23.8 +- 0.1 i' = 23.6 +- 0.2 z' = 23.5 +- 0.2 The magnitudes reported are measured from stacked images with a total integration time of 50 minutes (GCN 10782)." GRB 100514A 21:55:17.39 29:09:35.6 82.79 -19.67 Pegasus 2010/05/14 18:53:58 Swift Optical counterpart seen with m = 21.1. http://grb.sonoma.edu/images/swift_bursts/grb100514.jpg "This burst lasted about 30 seconds. Its light curve contained several overlapping peaks. XRT imaging of the field began 101 seconds after the trigger, and a bright, fading new x-ray source was found within the BAT error circle. UVOT images obtained around the same time did not reveal any optical source. Initial observations from the ground taken with the MASTER telescope in Russia did not find any OC to m > 17.0 71 seconds after the GRB trigger (GCN 10763). Similarly, images obtained with the 2 meter Faulkes Telescope South did not reveal an afterglow to R > 20.3 and i’ > 19.5. The images were made about 35 minutes after the trigger (GCN 10760). However, further analysis of the initial Swift/UVOT imagery revealed a marginally detected OC with m = 21.1. Additional images in various filters taken over the next approximately 2 hours did not show the OC. The afterglow was also detected from the ground using the 2.6 meter Shajn Telescope of the Crimean Astrophysical Observatory. At approximately 6 hours after the burst the object had dropped to R = 23.2 (GCN 10767)." GRB 100513A 11:18:26.86 03:37:38.1 255.5 57.67 Leo 2010/05/13 02:07:08 Swift Afterglow detected with R = 21.39 http://grb.sonoma.edu/images/swift_bursts/grb100513.jpg "The BAT light curve for this burst lasted about 50 seconds. It had a multi-peaked structure. The XRT began observing the field 127 seconds after the trigger and found an uncatalogued and fading x-ray source within the BAT error circle. An unfiltered 150 second finder chart image taken with the UVOT starting 130 seconds after the trigger showed no OC. However, NIR imagery from the 1.3 meter PAIRITEL on Mt. Hopkins, Arizona found a J = 17.7 object within the XRT error circle. The image was of 55 minute duration and began 46 minutes after the burst trigger. Images obtained simultaneously in H and K did not show the object, but no upper limits were quoted in the circular (GCN 10747). Subsequent observations over the next couple of hours showed that the object was indeed fading, confirming it as the GRB afterglow. In addition, the object was detected in H and K as well as J (GCN 10749). Images obtained from the SARA-North 0.9 meter telescope at Kitt Peak, at roughly the same time as the first Mt. Hopkins observations, did not detect the object to either R > 19.5 or I > 19 (GCN 10748). Using the 40 inch (1 meter) Nickel telescope at Lick Observatory near San Jose, California, observers were able to detect the afterglow in R at 21.39 +/- 0.25 magnitude. The Lick observers argue that the faint R magnitude (as compared to the H and K values) suggests an R-band dropout, and thus a high redshift for the GRB, somewhere between 4.6 < z < 6.0 (GCN 10750). This conclusion was confirmed by a spectrum obtained using the 8 meter Gemini North telescope in Hawaii. The spectrum showed a damped Lyman-alpha (DLA) system near 7000 angstroms (z ~4.8). In addition, absorption was detected from O I 1302, Si II 1304, C II 1334, C II* 1335, Si IV 1393, 1402, Si II 1526 and C IV 1548, 1550, all at a common redshift of z = 4.772. The spectrum also shows Lyman-alpha forest absorption blueward of the DLA system near 7000 angstroms (GCN 10752)." GRB 100511A 07:17:12 -04:39:00 220.02 3.59 Monoceros 2010/05/11 11:50:39 Fermi None has been reported The GBM showed several pulses in the burst light curve, which lasted 38 seconds. The spectrum was fit by a power law with exponential cutoff: index = -1.32 +/- 0.02, Epeak = 946.6 +134/-110 keV. GRB 100508A 05:04:59 -20:43:15 221.36 -32.29 Lepus 2010/05/08 09:20:42 Swift Afterglow detected with g'=22.0 http://grb.sonoma.edu/images/swift_bursts/grb100508.jpg "This was an image trigger, so the BAT light curve showed nothing. The XRT began observing the GRB 146 seconds after the trigger, finding a fading, uncatalogued x-ray source. The UVOT also imaged the field, but the initial unfiltered finder chart showed nothing to a limit of about mag 18. However, further analysis of the image showed an object with m = 18.87 in the initial image. A u image started at T+310 seconds showed the object to be at u = 19.25, and then another unfiltered image started at T+846 showed that the object had faded to m = 20.7 (GCN 10730). Initial reports from the ROTSE-IIa telescope in Australia contained only upper limits on the brightness: m > 16.5 at 158 seconds after the burst (GCN 10729). However, observers using the GROND multi-band imager on the larger aparture 2.2 meter telescope at La Silla in Chile did detect the afterglow. Their observations are listed in the table below (GCN 10734): g' = 22.0 +- 0.1 mag r' = 21.8 +- 0.1 mag i' = 21.5 +- 0.1 mag z' = 21.7 +- 0.2 mag J > 21.4 H > 20.8 K > 20.1 The burst was also seen in the Wide-band All-sky Monitor (WAM) aboard Suzaku. The WAM showed a multi-peaked light curve lasting about 103 seconds (GCN 10735). " GRB 100504A 17:02:17.22 -35:35:14.4 349.35 3.81 Scorpius 2010/05/04 19:20:59 Swift none has been reported http://grb.sonoma.edu/images/swift_bursts/grb100504.jpg "The BAT light curve for the burst had two peaks and lasted about 30 seconds. Swift slewed immediately to the burst and began observing with the XRT 63 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found in the BAT error circle. No afterglow was seen in UVOT the first images, obtained 71 seconds after the trigger. Observers from the ground had no luck in detecting an optical counterpart to this burst. Upper limits obtained at the SARA-South 0.6 meter telescope at CTIO 6h 42m after the trigger were 20th mag in R - The observers note that the extinction in the field from the Galaxy is large, with E(B-V) = 0.840 mag (GCN 10715). Fainter limits were reached from the GROND multi-band imager at La Silla (GCN 10717): g' > 23.2 r' > 22.2 i' > 21.6 z' > 21.2 J > 19.4 H > 19.1 K > 18.9 " GRB 100503A 09:50:00 04:00:00 232.87 40.97 Sextans 2010/05/03 13:18:03.89 Fermi 0 The GBM showed a multi-peaked light curve with a total duration of about 130 seconds. The spectrum was best fit by a power-law with exponential cutoff: index = -0.99 +0.06/-0.05, Epeak = 211.60 +18.30/-15.50 keV. GRB 100427A 05:56:41.1 -03:27:40 209.75 -13.75 Orion 2010/04/27 08:31:55 Swift 0 This burst was detected just as the satellite went into a pre-planned slew. As a result no onboard analysis was completed. The source was detected in later ground analysis. As a result, there are no prompt XRT/UVOT data because the satellite did not automatically detect and slew to the burst. A Swift Target Of Opportunity observation has been requested. GRB 100425A 19:56:44 -26:26:28 14.79 -25.28 Sagittarius 2010/04/25 02:50:45 Swift Optical counterpart seen with R = 20.55 http://grb.sonoma.edu/images/swift_bursts/grb100425a.jpg http://grb.sonoma.edu/images/afterglows/GRB100425A_finder.png z=1.755 "The BAT light curve for this burst had two peaks, one starting at the trigger time and lasting 8 seconds, and the other beginning 38 seconds after the trigger and lasting about 6 seconds. Swift slewed immediately to the burst and started observing with the XRT about 79 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found. No OC was found in an unfiltered UVOT image taken shortly after the XRT image. The limiting magnitude was 19.6. From the ground, and optical afterglow was reported from the VLT/X-shooter in Chile. The image, taken in R approximately 4 hours after the burst, showed two sources within the XRT error circle. One of the sources is seen in the DSS, the other, with a magnitude of R = 20.55 +/- 0.2, is not. A second epoch image taken nearly an hour after the first shows that the second object faded by 0.17 +/- 0.8 mag in the interval, suggesting that it is the GRB afterglow (GCN 100425A). Spectra were also obtained using the same telescope and instrument. The spectra cover wavelengths from 3000 to 25,000 angstroms. Absorption lines of MgII and FeII were seen at a common redshift of z = 1.755 (GCN 10684). The object was also observed with the GROND multi-band imager on the ESO 2.2 meter telescope at La Silla. The following magnitudes were measured 2.4 hours after the trigger (GCN 10683): g = 21.5 +- 0.2 r = 21.0 +- 0.1 i = 20.8 +- 0.1 z = 20.5 +- 0.1 J = 20.1 +- 0.2 H = 19.9 +- 0.2 K = 19.6 +- 0.2 " GRB 100424A 13:57:48 01:30:48 337.56 59.85 Virgo 2010/04/24 16:32:42 Swift none has been reported http://grb.sonoma.edu/images/swift_bursts/grb100424a.jpg "This was an image trigger, so there was no light curve information available from the BAT. The satellite slewed immediately to the burst, with the XRT beginning observations 120 seconds after the burst. A bright, uncatalogued source was found within the BAT error circle. No OC was found by the UVOT to a limit of about 19.6 mag (unfiltered). Ground-based observations from the NOT/ALFOSC were made in R, I and z about 6 to 7 hours after the trigger. No OC was detected to R > 22.5. Observations were hampered by the 85% full moon (GCN 10671). Limits of z > 23.2 were obtained using the William Herschel Telescope approximately 9 hours after the burst (GCN 10672). Many other observatories reported non-detections, but then Gemini-North observers using the NIR imager/spectrometer reported a possible afterglow with K = 19,9, J = 22.1. The observations were made approximately 14 hours after the burst. This is the only object visible within the XRT error circle (GCN 10682). " GRB 100423B 07:58:00 05:46:00 215.36 17.42 Canis Minor 2010/04/23 05:51:25 Fermi This burst had a single pulse lasting about 22 seconds. The spectrum was fit using a power law with exponential cutoff: index = -0.84 +/- 0.05, Epeak = 1034 +144/-117 keV. GRB 100423A 09:05:54 21:28:45 206.24 38.72 Cancer 2010/04/23 00:34:59 Swift none has been reported http://grb.sonoma.edu/images/swift_bursts/grb100423a.jpg This burst had a FRED light curve lasting at least 100 seconds. Because of the close proximity of the burst to the Moon (~10 degrees), Swift could not slew to the source. GRB 100420A 19:44:30.63 55:46:09.3 88.37 15.19 Cygnus 2010/04/20 05:22:42 Swift none has been reported http://grb.sonoma.edu/images/swift_bursts/grb100420a.jpg "This was an image trigger, so the BAT light curve does not show anything. The satellite slewed immediately to the burst. The XRT began observing 130 seconds after the trigger, finding a fading, uncatalogued x-ray source within the BAT error circle. No OC was found in the UVOT data immediately available. The XRT was able to follow the source for quite some time, measuring its decay rate and fitting its x-ray spectrum. See GCN 10639 for details. The ROTSE-III telescope at McDonald Observatory, Texas, observed the field beginning about 80 seconds after the burst. No new source was found to a limit of about 17th magnitude (GCN 10629). Observations using the SARA telescope on Kitt Peak also failed to find any OC, with somewhat dimmer limiting magnitudes: R > 19.0, I > 18.5 (GCN 10606). Similar limits were found from the MITSuME telescope at Okayama Observatory, Japan (GCN 10642). " GRB 100418A 17:05:27.09 11:27:42.3 31.46 28.67 Ophiuchus 2010/04/18 21:10:08 Swift m=20.7 http://grb.sonoma.edu/images/swift_bursts/grb100418a.jpg z=0.6235 "This burst had a single peak and lasted about 4 seconds. Swift was able to slew immediately to the burst, starting XRT observations 79 seconds afterward. A bright, fading x-ray source was found within the BAT error circle. Additionally, the UVOT found a possible afterglow candidate with m = 20.7 +/- 0.3 (unfiltered). From the ground, the GROND multiband imager on the 2.2 meter ESO telescope at La Silla detected a fading point source within the XRT/UVOT error circles. The source was seen in all bands. Preliminary magnitudes are as follows (GCN 10418): g' = 19.2 +- 0.1 r' = 18.8 +- 0.1 i' = 18.4 +- 0.1 z' = 18.1 +- 0.1 J = 17.7 +- 0.1 Additional observatories on the ground were able to confirm these results. In addition. spectra were taken using the VLT/X-shooter on Paranal in Chile. Lines from FeII, MgII, MgI, MnII, Ca H&K were seen in absorption, and [OII] was seen in emission, all at a common redshift of z = 0.6235 (GCN 10620). The spectrum was also measured using the Gemini North 8 meter telescope and GMOS spectrograph in Hawaii. The Gemini results confirm those from VLT (GCN 10624). " GRB 100415A 00:30:48 -16:41:00 97.3 -78.51 Cetus 2010/04/15 15:03:44.57 MAXI/GSC 0 A short x-ray transient was found in a MAXI/GSC scan (aboard the ISS). The transient lasted about 23 seconds. The hardness ratio of the transient suggests that it is a gamma-ray burst. GRB 100414A 12:48:27.04 08:41:35.1 300.6 71.55 Virgo 2010/04/14 02:20:21.99 Fermi m = 20.54 z=1.368 "This burst had a single pulse lasting about 26 seconds. The spectrum was fit with a power law and exponential cutoff: index = -0.58 +/- 0.01, Epeak = 627.6 +12.5/-12.1 keV. This burst occurred 70 degrees off the LAT bore sight, and an automatic repointing of the telescope was triggered. The LAT detected emission from the GRB source for 300 seconds following the GBM trigger, with 20 photons more energetic than 100 MeV detected. The most energetic photon from the source was 4 GeV (40 seconds after the trigger, GCN 10594). This field was observed by the Swift/XRT beginning about 48 hours after the trigger. An uncatalogued x-ray source was detected in 1.4 kiloseconds of observations. In these initial observations it was not possible to tell if the source was fading (GCN 10601). The Swift/UVOT also imaged the field. Observations were obtained 40.4 hours after the trigger and 53.2 hours after. There was some evidence for fading over that period: Filter T_start (hr) Exp(s) Mag Err White 40.38 765 20.54 +/- 0.10 White 53.20 3531 20.86 +/- 0.06 The Gemini North telescope (Hawaii) was able to obtain spectroscopy on the object on April 17.26, about 2.5 days after the burst. They detect an i’=20.37 +/- 0.03 object. Spectra in the range 4000 to 8000 angstroms show metal absorption line features from FeII 2374; FeII 2383; FeII 2587; MnII 2594; FeII 2600; MgII 2796, 2803, MgI 2853 all at z = 1.368 (GCN 10606). " score GRB 100413A 17:44:53.22 15:50:02.4 40.18 21.69 Hercules 2010/04/13 17:33:28 Swift none http://grb.sonoma.edu/images/swift_bursts/grb100413a.jpg zp~3.9 "This burst had a duration of 15 seconds. The satellite slewed immediately to the burst and began collecting XRT data 140 seconds after the trigger. A bright, uncatalogued fading object was found within the BAT error circle. The UVOT also collected data, but no object was seen to a limit of 19.6 magnitude (unfiltered). The UVOT data were obtained starting 149 seconds after the trigger. Ground-based observers also failed to detect any optical candidate.Observers at the Xinlong TNT telescope observed the field beginning about 10.5 minutes after the burst. No OC was found to fainter than about R ~ 20.5 (GCN 10583). At the 0.9 meter SARA telescope at Kitt Peak in Arizona, images collected 13.4 hours after the burst did not reveal any OC to a limiting magnitude of I ~ 19 (GCN 10587). Similar limits were found by the 2 meter aperture Faulkes Telescope - South in R and I. The images were started 231 seconds after the trigger (GCN 10589). The GROND multi-band imager obtained fainter limits (down to 25.3 in g’) in a set of images made 12 hours after the trigger (GCN 10592)." GRB 100413B 23:47:16 51:19:18 112.82 -10.29 Cassiopeia 2010/04/13 08:42:41 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100413b.jpg This is Swifts 500th GRB detection! It was not automatically followed up because the satellite was just undertaking a pre-planned slew when the burst went off. However, ground analysis did show a significant peak, building for approximately 12 seconds, then tailing off. The slew occurred at T ! 18 seconds. Target Of Opportunity observations were made and the results of those are pending. GRB 100401A 19:23:15.5 -08:15:25 29.12 -10.8 Aquila 2010/04/01 07:07:31.9 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100401a.jpg This burst was found in ground analysis of BAT data. It did not have high enough significance for an automatic trigger, but the ground analysis did uncover a significant source. The burst was also detected by the Fermi GBM. Target of Opportunity observations were made by Swift with the XRT and UVOT. These observations did not start until about 36 hours after the trigger. Neither instrument was able to detect any source (GCN 10569 and 10570). GRB 100325A 22:09:00 -28:36:00 20.87 -54.24 Piscis Austrinus 2010/03/25 06:36:08.02 Fermi 0 The GBM light curve had a single, structured pulse lasting 8.3 +/- 1.9 seconds. The spectrum was best fit by a power law with exponential cutoff: index = -0.45 +0.12/-0.11, Epeak = 159.3 +12.7/-10.8 KeV. GRB 100324A 06:34:26.8 -09:44:06.4 219.73 -8.17 Monoceros 2010/03/24 00:21:27 Swift 0 "This burst was detected as a rate increase in the BAT. It was found onboard, but was not significant enough to set off an automatic trigger. Ground analysis did reveal a significant source, however, but because this was automatically triggered, no XRT/UVOT data were immediately available. The BAT team requested Swift Target of Opportunity observations. Observers using the GROND multiband imager on the ESO 2.2 meter telescope at La Silla. The observations were done 23.3 hours after the GRB. No significant OC was found to i’ > 23.6, H > 21.6 (GCN 10545). " GRB 100322B 05:05:57.4 42:41:07 164.13 1.06 Auriga 2010/03/22 07:06:18 Swift http://grb.sonoma.edu/images/swift_bursts/grb100322b.jpg This burst, which lasted about 1.5 seconds, had a single peak. It was located very close to the galactic plane, making it possible that it was the result of a galactic source like a neutron star or x-ray binary. However, the burst spectrum, which is best fit by a simple power law, suggests a cosmological origin. No onboard source was detected, so no automated XRT/UVOT observations were performed. GRB 100322A 23:20:00 -10:13:00 66.7 -62.62 Aquarius 2010/03/22 01:05:09 Fermi The GBM light curve had multiple peaks, and the burst had a duration of 37 seconds. The spectrum was best fit by a Band function with alpha = -0.88 +/- 0.02, beta = -2.15 +/- 0.05 and Epeak = 309 +/- 16 keV. GRB 100316D 07:10:30.98 -56:15:24.1 266.9 -19.76 Carina 2010/03/16 12:44:50 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100316d.jpg "This was an image trigger, and it is possible that the burst has a low level peak about 100 seconds long. The satellite slewed immediately to the burst, with the XRT detecting a bright, uncatalogued xray source. The XRT data collection started 138 seconds after the trigger. The UVOT also imaged the field, but in a 150 second finder chart starting 148 seconds after the trigger, no OC is found. However, part of the UVOT data was not transmitted to the ground, so the overlap between the UVOT and XRT is uncertain, as the precise error circle for the XRT. Ground-based observations from GROND/2.2 meter ESO telescope, Gemini/GMOS and VLT/X-shooter all detect a faint DSS galaxy (redshift z = 0.054, GCN 10512) within the XRT error circle. The galaxy contains two compact sources, but neither seems to be fading, and they are likely to be bright areas of the galaxy in any case (e.g., H II regions, see GCN 10513, 10514 and 10516). Gemini observers report seeing a bright object close to the galaxy core, but it is not clear if the source is related to the GRB (GCN 10524). Detailed analysis of the xray data from the XRT puts the most likely redshift for this burst at 0.014 < z < 0.28, which is consistent with the burst being associated with the galaxy reported earlier (GCN 10517)." Observers using the VLT in Chile observed the OC on 23 March and report the emergence of a possible supernova spectrum from the source (GCN 10543). GRB 100316C 02:09:08.85 -67:59:29.1 292.3 -47.5 Hydrus 2010/03/16 08:57:59 Swift optical counterpart at g' = 23.7 http://grb.sonoma.edu/images/swift_bursts/grb100316c.jpg "This burst had a single peak lasting about 7 seconds. Swift slewed immediately to the burst and began observing with the XRT and UVOT. In images taken 78 seconds after the trigger, the XRT found an uncatalogued xray source within the BAT error circle. The UVOT, beginning 81 seconds after the trigger, did not detect any OC in a 150 second unfiltered exposure. The limiting magnitude was about m = 19.6. Imaging from the BOOTES-3 0.6 meter telescope in Blenheim, New Zealand, did not find any OC down to a limiting magnitude of m = 18.5. The observations started 49 seconds after the trigger and continued for ~40 seconds (GCN 10497). Observers using the GROND multiobject imager fared better. Their images started 15.8 hours after the trigger, and using the multiband camera mounted on the ESO 2.2 meter telescope at La Silla, they found a faint object, with g’=23.7 +/- 0.1, r’=24.4 +/- 0.1. They report only upper limits in i’ and z’. The source was not present in catalogs and was placed right at the edge of the XRT error circle. Further observations and reductions were ongoing (GCN 10516)." GRB 100316B 10:53:57.15 -45:28:21.6 282.29 12.64 Vela 2010/03/16 08:01:36 Swift NIR counterpart observed at I = 15.61. http://grb.sonoma.edu/images/swift_bursts/grb100316b.jpg 1.180 "The BAT light curve for this burst had a multi-peaked structure and a duration of about 5 seconds. Swift slewed immediately to the burst and began observations with the XRT and UVOT. At 64 seconds the XRT began observing the field and detected a fading, uncatalogued xray source. 2 seconds later the UVOT started a 150 second unfiltered finder chart exposure and also detected a source at the GRB position. The preliminary UVOT magnitude was m = 18.36. From the ground this afterglow was detected by the GROND multiband imager in Chile, at magnitudes g’ = 19.2 +/- 0.1, r’ = 18.9 +/- 0.1 (GROND zero point magnitudes, uncorrected for extinction). The images were made beginning 16 minutes after the trigger (GCN 10493). The afterglow was also observed from the PROMPT telescopes on Cerro Tololo. In images taken 32 seconds after the trigger using four of the PROMPT telescopes, the OC was seen in all filters. It had a magnitude of I = 15.61 +0.16 / -0.14 at T0+32. From T0+32 seconds to T0+2.1 minutes the OC faded with a power law index of about -1.0. From 2.1 minutes to 35 minutes it faded more slowly, with an index of about -0.3. From 35 to 41 minutes the OC re-brightened, with a power law index of +5.4. It then faded with an index of -0.6 until T0+49 minutes, then more rapidly with an index -1.7 to T0+95 minutes, at which point it had a magnitude of R = 19.51 + 0.33 / - 0.26 (GCN 10494) In addition to the reported photometry, a spectrum was obtained from the VLT and X-shooter spectrograph. The spectra were obtained beginning 40 minutes after the trigger and in a set of four 600 second exposures. The wavelength ranged covered is 3200 to 24000 angstroms. Absorption features from Fe II (1608), Al II (1670), Al III (1854), Fe II (2344), Fe II (2374), Fe II (2382), Mg II (2796, 2803) and Mg I (2852) were seen, all with redshift z = 1.180. The wavelength solution is preliminary for these data, so the redshifts might change under further analysis." GRB 100316A 16:48:07 71:49:31 103.81 35.13 Draco 2010/03/16 02:23:00 Swift none has been reported. "This burst had a single peak lasting about 10 seconds. Because of an observing constraint there is no prompt XRT or UVOT data. Swift had to wait for 52 minutes before slewing. However, in imaging started 51.8 minutes after the trigger, the XRT detected an uncatalogued x-ray source within the BAT error circle (GCN 10485). The UVOT also observed the field, beginning 53 minutes after the trigger. No OC was detected to m = 19.6 (unfiltered, GCN 10486). Ground-based observations carried out with the 1.23 meter telescope at Calar Alto, Spain revealed a faint object, R ~ 20.5, at the position of the XRT source. The object does not seem to be present in the digitized sky survey (GCN 10488). " GRB 100305A 11:13:28.3 42:24:10.50 169.11 64.9 Ursa Major 2010/03/05 09:05:38 Swift Counterpart seen at r' = 23.95 http://grb.sonoma.edu/images/swift_bursts/grb100305a.jpg "This burst had a single peak lasting about 20 seconds. The XRT started observing the field 139 seconds after the trigger, finding a bright uncatalogued x-ray source within the BAT error circle. The UVOT also imaged the field, but it found no optical candidate in its 122 second unfiltered image. Ground-based followup observations from the Palomar 60 inch telescope in g’, r’, i’ and z’ starting about 3.5 minutes after the trigger yielded only upper limits (r’ > 22.0 GCN 10471). Faint upper limits were also reported in JHK observations from the 1.3 meter PARITEL on Mt. Hopkins, Arizona. These had J > 19.2 for any OC in the field (GCN 10472). The Gemini North 8 meter telescope on Mauna Kea, Hawaii imaged the field beginning about two hours after the trigger. In their 300 second r’ image they report a source within the XRT error circle with r’ = 23.95 +/- 0.30, and also i‘ = 23.71 +/- 0.06 (GCN 10473). No object is seen in z’ to limiting magnitude z’ > 23.42 (GCN 10478). " GRB 100302A 13:01:22 74:34:50 122.04 42.53 Draco 2010/03/02 19:53:06 Swift Counterpart seen at i'=22.01 http://grb.sonoma.edu/images/swift_bursts/grb100302a.jpg 4.813 "Swift slewed immediately to this burst, which consisted of a broad peak that started about 40 seconds after the trigger and lasted about 35 seconds. The XRT began observing the field 125 seconds after the trigger, finding a bright, fading, uncatalogued x-ray source within the BAT error circle. The UVOT made a 150 second unfiltered exposure beginning 132 seconds after the trigger, but no OC was seen. From the ground, the field was observed only 2.7 minutes after the trigger from the 40 cm Dolomiti Astronomical Observatory using the PROMPT automation system. In a series of stacked exposures with mean time from the trigger of 73.3 minutes, no OC is detected to R > 20.3 (GCN 10459). A series of observations from the Lulin 1 meter telescope in Taiwan showed a marginal detection in R (~21) 16 minutes after the burst. The object was clearly detected at I = 19.9 44 minutes after the burst, but then morning twilight interrupted the observations (GCN 10461). Additional optical observations taken from Russia with the MASTER robotic telescope detected an object at m = 16.9 at T+139 seconds. The object had faded to m = 18.5 in stacked images obtained from 139s to 4046 s (GCN 10463). The object was not detected in a set of observations with the 60 cm robotic telescope in Crni Vrh, Slovenia. These images were begun 194 seconds after the trigger in moonlit conditions. The first has a limiting magnitude of R > 18.3, while a series of summed images totaling 1200 seconds goes a bit deeper to R > 19.6 (GCN 10464). Observations using the Gemini North telescope on Mauna Kea in Hawaii found a source with i’ = 22.01 +/- 0.05 in a 300 second image taken about 11.5 hours after the trigger. A spectrum was also obtained, but no features were reported (GCN 10466). Subsequent spectral of the spectrum did reveal a sharp rise in continuum redward of 7100 angstroms. In addition, there are narrow absorption features consistent with NV, Si II, Si II* and C II, all at a redshift of z = 4.813. This is consistent with an interpretation of the continuum rise at 7100 angstroms as being due to the Lyman limit (GCN 10466). " GRB 100224A 05:33:52.1 -07:59:37 211.33 -20.86 Orion 2010/02/24 15:20:10 Swift 0 This burst was triggered in the BAT, but no source was found onboard. A source was found in ground analysis. The burst had two main peaks. The first was larger and centered at T+0.2 seconds. It lasted 0.1 seconds. The second was centered at T+0.5 seconds and lasted 0.3 seconds. GRB 100224B 17:58:00 -17:05:00 11.66 3.59 Sagittarius 2010/02/24 02:40:55.48 Fermi 0 The light curve for this burst had three distinct peaks. Its total duration was about 77 seconds, starting at T-5.6 seconds. The spectrum was fit by a power law with exponential cutoff: index = -1.36 +0.07 / -0.06, Epeak = 181.40 +31.50 / - 23.60 keV. GRB 100223A 06:56:00 02:48:00 210.96 2.29 Monoceros 2010/02/23 02:38:09.31 Fermi 0 A short, soft peak triggered the GBM for this burst. It had a duration of 0.05 seconds and was followed after a few milliseconds by a harder one. The total duration for the burst was 0.206 seconds. The spectrum was fit by a power law with exponential cutoff: index = -0.31 +/- 0.08, Epeak = 1143 +/- 109 keV. GRB 100219A 10:16:52 -12:33:32 254.53 35.4 Hydra 2010/02/19 15:15:46 Swift Counterpart seen at m=20.70 http://grb.sonoma.edu/images/swift_bursts/grb100219b.jpg " Swift slewed immediately to this burst, which as an image trigger had no interesting light curve features. Later analysis of downlinked BAT data showed a triangular shaped light curve beginning around T-10 seconds, peaking about 40 seconds later, and ending near T+50 seconds. A fading, uncatalogued x-ray source was found within the BAT error circle. The XRT observations were begun 178 seconds after the trigger. No source was found inside the XRT error circle in near-simultaneous images obtained with the UVOT. However, an uncatalogued source was found 1.7 arcseconds outside of the XRT error circle. The object had magnitudes m = 20.70 +/- 0.34 and u = 21.00 +/- 0.56. It was not clear if this source was associated with the GRB (GCN 10432). Further observations and analysis (GCN 10436) showed that the source was fading, indicating that it was indeed the optical afterglow of the GRB, though superimposed on a possible host galaxy (GCN 10433). The GROND multiband imager was used to obtain data on the GRB field simultaneously in g’, r’, i’. z’, and JHK. The imager was mounted on the 2.2 meter MPI/ESO telescope at La Silla, Chile. The images were obtained 8.7 hours after the GRB trigger. The OC is detected, as is the possible host galaxy. However, the OC is detected only in r’ and redward; no g’ object is detected. This spectral energy distribution suggests a redshift around z = 4.5 (GCN 10439). The spectra of the GRB and possibly associated galaxy were obtained using the VLT+X-shooter spectrograph. No flux is seen from the OC blueward of ~5310 angstrom, and there is another spectral break around 7060 angstrom, indicative of the Lyman break and onset of Lyman-alpha forest at a common redshift of z = 4.8. The adjacent galaxy has a redshift of only z = 0.25, and so is not associated with the GRB (GCN 10441). Additional spectral data obtained at the Gemini South telescope in Chile were roughly consistent with, though somewhat lower than, the above redshift values from the VLT. This was true for both the OC and the nearby galaxy (GCN 10443)." GRB 100216A 10:17:03.2 35:31:27.5 188.83 56.21 Leo Minor 2010/02/16 10:07:00 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100316a.jpg "Though the BAT triggered on a source at the position, no source was found onboard. Subsequent ground analysis did find a source at 6.8 sigma. No automated followup was performed because no onboard source was detected. The burst was also detected by the Fermi GBM. The burst had a single peak that lasted 0.3 seconds. Ground-based imaging was performed about three days after the burst from the Keck Observatory in Hawaii. In 660 seconds of simultaneous imaging in R and g, no new source was detected down to R > 22 (GCN 10429)." GRB 100213B 08:17:08.59 43:26:50.2 176.93 33.34 Lynx 2010/02/13 22:58:34 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100213b.jpg "This burst had a FRED-like structure and a duration of about 30 seconds. The XRT began observing about 150 seconds after the trigger, finding a bright, uncatalogued source. The UVOT also imaged the field, beginning 157 seconds after the trigger. In a 77 second unfiltered image, no OC is detected to a limiting magnitude of 20.5 (3-sigma). Ground-based imaging was done using the NOT, however, because of poor weather conditions only a single 5 minute exposure was made in R. The exposure was started about 19 minutes after the trigger. An object with R ! 21.5 was detected just outside the XRT error circle, about 8 arcseconds from the x-ray position. The object is elongated and is not visible in DSS plates. An additional very faint image is reported inside the XRT error circle, with a magnitude of R ! 22.2, near the detection limit of the image (GCN 10413). Additional ground-based images were obtained using the 1.3 meter PERITAL on Mt. Hopkins, Arizona beginning about 4 hours after the trigger. Images in J, H and Ks failed to detect any afterglow within the XRT error position. Nor was any object detected at the NOT positions reported (above). Limiting magnitudes in the filters were t_mid(h) exp(s) filt U. Limit (3 sig) 4.44 2387 J > 19.2 4.44 2387 H > 18.2 4.44 2387 Ks > 17.1 The Gemini North telescope also observed the field. They do detect the NOT-reported image at the edge of the XRT error circle in a 2 minute r-band image. The subsequently obtained a spectrum of the object, detecting [OII]3727, H-beta and [OIII]5007 at a common redshift of z = 0.604. It is not clear that this object is related to the GRB (GCN 10422). Imaging was also done using the 14 inch Goddard Robotic Telescope beginning 56 minutes after the trigger. In 59 R images each of 60 second exposure, no OC is detected, either in the individual images or when they are combined (GCN 10426)." GRB 100213A 23:17:34.01 43:22:46.4 105.38 -16.27 Andromeda 2010/02/13 22:27:48 Swift None has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100213a.jpg "This burst showed two main peaks and had a total duration of about 4 seconds. The XRT began observing the field about 73 seconds after the trigger, detecting an uncatalogued x-ray source within the BAT error circle. The UVOT observed the field beginning 76 after the trigger, but no credible optical afterglow is reported. Observations from the SARA telescope on Kitt Peak, Arizona were started approximately 4 hours after the trigger. No OC was detected in the 20 minutes of stacked images. The limiting magnitude was R > 20 (based on USNO star comparisons, GCN 10415). Additional ground-based images taken with the 14-inch Goddard Robotic Telescope in Maryland did not find any OC. The images were begun about 1.2 hours after the burst and continued for about an hour in the R filter. The limiting magnitude is estimated as R > 17.5 (GCN 10435)." GRB 100212A 23:45:50 49:29:50 112.13 -11.99 Cassiopeia 2010/02/12 14:07:22 Swift Optical counterpart at R = 20.3 http://grb.sonoma.edu/images/swift_bursts/grb100212.jpg "This burst had a single peaked light curve lasting about 2 seconds. Swift slewed immediately upon triggering, and XRT observations commenced 58 seconds later. A bright, uncatalogued x-ray source was detected. The UVOT began observing 280 seconds after the trigger, but no OC was found in the initial 250 second long finder chart exposure. The limiting magnitude was U > 19.2. Ground-based observations from the NOT showed a faint object, R = 20.3, near the center of the XRT error circle approximately 6 hours after the GRB trigger. No corresponding object is evident in the DSS plate of the region (GCN 10402). The object was also seen in images from the Mt. Lemmon 1 meter telescope in Arizona. In those images, taken 12 hours after the trigger, the object had faded to R = 22.5 +/- 0.2 (GCN 10407)." GRB 100206A 03:08:42 13:10:04 166.88 -37.73 Aries 2010/02/06 13:30:05 Swift GRB 100206A 03:08:38.81 13:09:28.4 166.88 -37.74 Aries 2010/02/06 13:30:05 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100206.jpg "This was a short burst, with a single peak of 0.3 second duration. The satellite slewed immediately to the burst, with the XRT beginning observations 75 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The UVOT also observed the field, beginning 78 seconds after the trigger, but there was no OC evident in the 150 second unfiltered finder chart images. In the initial hours after the burst, no OC was reported, despite attempts using GROND at La Silla, with upper limits (GCN 10383) g' > 22.8, r' > 23.0, i' > 22.4, z' > 22.2, J > 21.0, H > 20.6 K > 20.3 As well as the 0.6 meter TELMA robotic telescope, I > 21 (GCN 10384). Images were also made in the first minute after the burst, but with a much smaller aperture, from the University of Miyazaki (RIMOTS, 30 cm). These unfiltered images had limiting magnitudes -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 13:31:14 13:31:44 1 14.1 13:31:14 14:26:55 29 17.4 --------------------------------------------------------------- Finally, a candidate OC was detected using the William Herschel Telescope on La Palma in observations made approximately 7 hours after the trigger. The source was located just outside the XRT error circle and was detected in both I and z (magnitudes are not reported! GCN 10386). Spectroscopy was obtained for the possible host galaxy (GCN 377) using the Keck-I + LRIS. A very red continuum is evident, as are emission lines of H-alpha and [NII] at z = 0.41. No other lines are visible, and no trace is seen at the position of the GRB. If this galaxy is indeed the host, then the projected distance to the GRB at the measured redshift is 35 kiloparsecs (GCN 10389)." GRB 100205A 09:25:37 31:44:21 194.12 45.36 Leo 2010/02/05 04:18:43 Swift GRB 100205A 09:25:32.99 31:44:25.8 194.12 45.34 Leo 2010/02/05 04:18:43 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100205.jpg "This burst had a duration of approximately 30 seconds. Swift slewed immediately to the burst and started observing with the XRT 175 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The UVOT also observed the field, but in 150 second unfiltered images begun 177 seconds after the trigger, no OC was found. Ground based observers searched for an afterglow using the Nordic Optical Telescope (NOT). In R and I imaging done 39 and 59 minutes after the trigger, respectively, there was no OC found. Limits were R > 23.7 and I > 23.2 (GCN 10362). Additional ground based images from LOTIS on Kitt Peak also failed to find an afterglow brighter than V = 18 in the first ~10 minutes after the burst (GCN 10364). Gemini South also failed to detect any afterglow (GCN 10365), but Gemini North detected a point source in K-band images taken 2.6 hours after the trigger. The magnitude of the source was K ~ 20.2. The source also showed marginal detections in J and H bands (GCN 10366). Subsequent analysis of the Gemini N photometry produced J_AB > 23.37 mag (1-sigma UL) H_AB = 23:54 +- 0.22 mag K_AB = 21.91 +- 0.20 mag Which implies 11 <~ z < ~ 13.5 if the extremely red K - H colors are assumed caused by Lyman-alpha absorption in the H bandpass. However, other possibilities are not ruled out, including host extinction, unusual intrinsic colors for the afterglow or large contribution to the light by the host galaxy (GCN 10374)." GRB 100203A 06:24:54 04:47:33 205.63 -3.69 Monoceros 2010/02/03 18:31:07 Swift 0 This was a weak burst, too low in significance to trigger an automatic detection; it was found in ground analysis of BAT data. The light curve showed three well-separated peaks, each about 10 seconds long, occurring at T-50 seconds, T+0 seconds and T+60 seconds. It is possible that the source is a galactic transient and not a GRB. GRB 100131A 08:02:00 16:29:00 205.45 22.83 Cancer 2010/01/31 17:30:57.67 Fermi 0 This burst lasted 6.2 seconds. It consisted of a single bright spike with substructure. The spectrum was best fit by a Band function: alpha = -0.63 +/- 0.05, beta = -2.21 +/- 0.05, Epeak = 132.10 +/- 6.28. GRB 100122A 05:16:48 -02:42:00 204.18 -22.22 Orion 2010/01/22 14:47:37.31 Fermi 0 http://observ.pereplet.ru/images/GRB100122A/grb100122A.jpg http://observ.pereplet.ru/images/GRB100122A/grb.html "This burst had two pulses, the first a weak one, followed by a much stronger one beginning 21 seconds later and lasting 6.6 seconds. The spectrum is fit by a Band function with alpha = -0.98 +/- 0.05, beta = -2.31 +/- 0.03 and Epeak = 45.6 +/- 1.5 keV. Ground-based imaging was done using the MASTER robotic telescope in Blagoveschensk, Russia. The images are from the telescope itself, with a limiting magnitude of m ~ 17, and from the Very Wide Field Camera which has a limit of m ~ 11.5. An image showing the region of the burst with the Fermi error boxes superimposed in linked." GRB 100119A 19:57:18 -53:09:36 345.1 -31.08 Telescopium 2010/01/19 18:25:25 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb100119.jpg 4.8 Sun observing constraint prevented Swift from slewing to this burst immediately. The BAT showed multiple overlapping peaks in the lightcurve for this burst, which lasted about 25 seconds. Because of the solar constraint there will be no XRT or UVOT observations possible for 26 days. GRB 20100117A 00:45:04.67 -01:35:46.3 119.25 -64.42 Cetus 2010/01/17 21:06:19 Swift No optical counterpart was observed. http://grb.sonoma.edu/images/swift_bursts/grb100117.jpg "This burst was a single spike lasting 0.4 seconds. Swift slewed immediately to the field of view and began observing with the XRT 80 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the region, but no OC was obvious. Observers using the Nordic Optical Telescope at La Silla began observing the field approximately 20 minutes after the trigger. A faint object, only marginally detected, was seen in a 900 second R-band image. The object was not seen in a set of co-added K-band images (GCN 10337). However, this source seemed to coincide with archival images taken at the CFHT (GCN 10339), indicating that it could not be the afterglow of the GRB. The same archival sources, and no others, were detected by imaging from the Magellan/Baade 6.5 meter telescope taken 3.9 hours after the burst trigger (GCN 10340). Subsequent analysis of the XRT data excluded all but one of the four objects from the XRT error circle; the faint object first reported by NOT was one of the excluded objects (GCN 10343). The Gemini North telescope was used to obtain further images and spectra of the objects in the field. One object was shown to be an M dwarf star by its spectrum, while two other objects showed no spectral features (GCN 10346). Deep images showed that one of these remaining objects faded by 0.23 +/- 0.06 magnitudes over 25 hours, suggesting that it might host the GRB. Image subtraction reveals an object offset from the center of the possible host (GCN 10349)." GRB 100116A 20:20:04.8 16:24:00 58.04 -11.15 Sagitta 2010/01/16 21:31:00.24 Fermi 0 This burst had two separate peaks separated by more than 60 seconds. There was essentially no emission evident between the peaks. The total duration of the burst was approximately 110 seconds. Both peaks were best fit with a power law plus high energy cutoff for the spectra. The first peak had an index of -0.92 +/- 0.15 and Epeak = 240 +60/-40 keV. The second peak had an index of -1.02 +/- 0.017 and Epeak = 1240 +/- 90 keV. The burst was also seen by the LAT, which saw an increase in the flux coincident with the second peak. Most of the energy was detected below 100 MeV (GCN 10333). score GRB 100115A 00:13:28.16 -00:49:35.4 102.25 -62.16 Pisces 2010/01/15 11:15:19 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb100115.jpg "This burst was detected on the ground during data collected during a pre-planned slew of the satellite. It was found as part of the BAT Slew Survey. The burst had a FRED peak with a duration of about 3 seconds. No flux was detected above 100 keV. The source was observed as a Target Of Opportunity starting about 11 hours after the trigger. A single x-ray source was found within the BAT error circle in 2.5 kiloseconds of XRT observations (GCN 10326). UVOT also made observations simultaneously with the XRT, but no optical source was found to coincide with the XRT source (GCN 10327). The 0.9 meter SARA telescope at Kitt Peak National Observatory in Arizona made a 1200 second observation of the field beginning 15 hours and 20 minutes after the burst. A faint object, R ~ 22, was found within the XRT error circle. There is no corresponding object in the SDSS, which goes deeper than the SARA image, thus it is possible that this source is the GRB afterglow (GCN 10328). Additional observations of the field were taken using the 2.56 meter NOT at La Silla. The images have a limiting magnitude of i’=24.0, and a single extended object is seen within the XRT error circle (GCN10331). This extended object matches the position of the object reported by SARA (GCN 10332). Observations of this object using the Gemini North telescope taken on Jan 16 and 17, respectively, found that it had faded by approximately half a magnitude in both r and g, suggesting that the extended object is the host of the GRB and its afterglow (GCN 10335)." GRB 100111A 16:28:09 15:33:24 31.58 38.62 Hercules 2010/01/11 04:12:49 Swift Optical counterpart at m = 17.58. http://grb.sonoma.edu/images/swift_bursts/grb100111.jpg "This peak had a slight precursor followed by a main peak with a FRED profile. The total duration was about 30 seconds. Swift slewed immediately and began observing the the XRT 63 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The UVOT took a 150 second finder chart exposure beginning 67 seconds after the trigger. An OC with approximate magnitude m = 17.58 was seen in the initial image. The burst also triggered the GBM aboard Fermi (GCN 10319). From the ground, the afterglow was seen by the Nordic Optical Telescope at R = 19.46 +/- 0.05 in observations taken 73 minutes after the trigger (GCN 10318). The afterglow was not seen by observers at PARITEL in Arizona in NIR observations taken about eight hours after the burst. Lower limits are below (GCN 10324): post_burst t_mid(h) exp(s) filt U. Limit (3 sig) 8.60 2223 J > 19.0 8.60 2223 H > 18.5 8.60 2223 Ks > 18.0 " GRB 100130B 05:10:00 20:21:00 182.76 -11.47 Taurus 2010/01/10 18:38:35.46 Fermi This burst had four peaks, with a total duration of about 90 seconds. The spectrum by a power law with exponential cutoff: the index is -1.22 +/- 0.04, with Epeak = 208.00 +/- 17.10 keV. GRB 100130A 01:19:00 -25:12:00 197.16 -83.52 Sculptor 2010/01/10 17:29:24.14 Fermi 0 This GRB had an initial soft, weak peak. A second stronger peak followed at T+50, and then another weaker one at T+75 seconds. The total duration of the burst was about 106 seconds. The spectrum was fit by a power law with exponential cutoff: index = -0.97 +/- 0.06, Epeak = 100.50 +/- 4.77 keV. GRB 100103A 07:29:29.46 -34:29:24.9 247.78 -7.87 Puppis 2010/01/03 17:41:32 INTEGRAL 0 http://ibas.iasf-milano.inaf.it/products/100103Alc.jpg "This burst had a duration of 40 seconds. The Swift satellite observed the field 54 seconds after the INTEGRAL trigger, finding an uncatalogued x-ray source with the XRT. No source was found with the UVOT, with lower limits v > 20.44, u > 20.70 (GCN 10310). Additional Swift/XRT observations showed that the source was fading approximately 55 hours after the trigger, thus confirming that it was the GRB afterglow (GCN 10313)." GRB 091231A 15:40:19 -08:44:15 357.71 35.6 Libra 2009/12/31 17:44:17 Swift GRB 091230 08:51:39.18 -53:53:52.7 272.08 -6.07 Vela 2009/12/30 06:27:30 INTEGRAL 0 http://ibas.iasf-milano.inaf.it/091230.html "This GRB had a duration of about 120 seconds. The GRB was observed using the GROND multiobject imager on the 2.2 meter telescope at La Silla, Chile. Observations were begun only 2.9 minutes after the burst. The afterglow was detected in all filters. Magnitudes are given below (GCN 10299): Filter T_mid[s] Exp[s] AB Mag MagErr --------------------------------------- g' 390 4x 66 21.63 0.07 r' 390 4x 66 20.76 0.04 i' 390 4x 66 20.45 0.05 z' 390 4x 66 20.22 0.05 J 403 24x 10 19.75 0.12 H 403 24x 10 19.58 0.14 K 403 24x 10 19.26 0.15 Followup observations taken using the Swift XRT and UVOT did not find any afterglow. The observations were taken approximately 9 hours after the trigger (GCN 10302)." GRB 091229A 04:59:15 -55:02:31 263.11 -37.84 Dorado 2009/12/29 02:07:04 Swift GRB 091221A 03:43:11.40 23:14:28.3 166.5 -24.76 Taurus 2009/12/21 20:52:52 Swift Optical counterpart at m ~ 17.4 http://grb.sonoma.edu/images/swift_bursts/grb091221.jpg http://www.rotse.net/images/gsb380311_3c011-020_key.jpg "This burst contained two peaks, one lasting from T0 to T+15, and another stronger peak from T+15 to T+40. There is some overlap in the field with the flaring AGN A0535+262, but the light curves from the two objects are mostly distinguishable. Swift slewed immediately to the burst and began observing with the XRT about 72 seconds after the trigger. A bright, fading x-ray source was found. Similarly, the UVOT began imaging the field 79 seconds after the trigger, however, the initial optical images showed no OC to a limiting magnitude of m = 19.6 (3 sigma). From the ground, the ROTSE-IIIc telescope at Mt. Gamsberg, Namibia began observing the field 26 seconds after the burst, finding an m = 17.4 object within the XRT error circle. The object is not present in the Digitized Sky Survey, 2MASS or MPChecker (GCN 10284). Additional analysis of the UVOT data taken immediately after the trigger confirmed the presence of the source (GCN 10285). The object was also detected in five of seven bands with the GROND multi-band imager at La Silla, Chile. Magnitudes and upper limits are as follows (GCN 10286): g' = 22.90 +/- 0.30 r' = 22.27 +/- 0.30 i' = 21.95 +/- 0.30 z' = 22.20 +/- 0.30 J = 20.16 +/- 0.20 H > 19.9 K > 19.1 " GRB 091215A 16:08:10 51:23:42 80.11 46 Draco 2009/12/15 15:39:06 Swift GRB 091208B 01:57:34.06 16:53:22.7 144.85 -43.15 Aries 2009/12/08 09:49:57 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091208b.jpg 1.063 "Swift slewed immediately to this burst, which showed a double-peaked light curve. The burst lasted about 15 seconds. The afterglow was detected by both the XRT and the UVOT, with the former beginning to observe the field 115 seconds after the trigger, and the latter 4 seconds thereafter. The UVOT initial magnitude estimate is m = 17.9, unfiltered. On the ground, the ROTSE-IIIb telescope at McDonald Observatory in Texas began observing 30 seconds after the trigger. Their initial imaging showed no OC to a limiting magnitude of m ~ 17.3 (unfiltered, GCN 10254). Observers using the BOOTES-3 robotic telescope in New Zealand do report seeing the afterglow in images begun 45 seconds after the trigger, but they give no magnitude (! -GCN 10255). Observations from the MITSuME 50 centimeter telescope at Akeno, Japan detected the OC in all three bands observed: g’=17.2,+/-0.2 Rc=16.1+/-0.1 and Ic=15.5+/-0.1 (GCN 10260). The OC was also observed by several other ground-based facilities. A spectrum obtained from the Gemini North telescope was able to provide a redshift of z = 1.063 based on absorption from MgII (2796,2803), Mg I (2583), Fe I (2967), Fe II (2586, 2600) and Mn II (2576, 2594, 2606) in their spectrum covering the range from 4000 to 8400 angstroms (GCN 10263)." GRB 091208A 00:01:06 65:40:25 117.77 3.31 Cassiopeia 2009/12/08 08:46:00 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091208a.jpg "Earth limb constraint prevented Swift from slewing immediately to this burst. The BAT light curve had a FRED structure and lasted about 30 seconds. The constraint was in effect until 49 minutes after the trigger. However, about an hour after this burst, a second burst, GRB 091208B went off, and the satellite was then occupied with those observations. From the ground, observations were undertaken with the RIMOTS of the University of Miyazaki, Japan. The observations were begun 19 minutes after the trigger. They show no new optical sources to limiting magnitudes of 15.8 in the first frame and to 17.3 in 33 stacked observations over a period of ~44 minutes (GCN 10261)." GRB 091202 09:15:20.17 +62:32:58.1 152.18 40.21 Ursa Major 2009/12/02 23:10:12 INTEGRAL 0 The burst had a duration of about 50 seconds. Though the alert for this object was reported by INTEGRAL, Swift was able to get improved positional data using the XRT/UVOT. The Swift data also show that the x-ray source is fading, but the early data (to T+26.9 kiloseconds) is not good enough to fix the decay rate (GCN 10243). GRB 091130B 13:32:35.68 34:05:17.8 73.63 78.75 Canes Venatici 2009/11/30 17:59:04 Swift http://grb.sonoma.edu/images/swift_bursts/grb091130b.jpg "This burst had two, or possibly three, peaks with a total duration of about 100 seconds. The satellite slewed immediately to the burst and started observing with the XRT 85.4 seconds after the trigger. A bright, uncatalogued x-ray source was detected within the BAT error circle. The UVOT also imaged the field, beginning 94 seconds after the trigger. No OC was apparent in the 150 second finder chart exposure. " GRB 091128 08:30:00 01:42:00 223.14 22.61 Hydra 2009/11/28 06:50:34.64 Fermi 0 The GBM light curve shows a single structured peak lasting about 97 seconds. The spectrum was best fit by a power law with exponential cutoff: index = -0.99 +/- 0.02, Epeak = 178.8 +/- 5.6 keV. GRB 091127A 02:26:19.89 -18:57:08.5 197.4 -66.74 Cetus 2009/11/27 23:25:45 Swift Optical counterpart at m = 16.21 0.490 "Swift was not able to slew immediately to this burst because of Earth limb constraint. The BAT light curve showed a multipeaked structure and had a duration of about 10 seconds. The burst exited constraint and Swift was able to image the field 3219 seconds after the trigger. A magnitude 16.21 object was detected with the UVOT (unfiltered 150 seconds exposure). It was located 40.9 seconds from the center of the BAT error circle (GCN 10193). This afterglow was also detected from the ground by several observing groups. Using the 2 meter Liverpool Telescope, observations begun 2.35 minutes after the trigger revealed the fading candidate to have a magnitude around R = 15.0 (GCN 10192). The 60 centimeter REM telescope also detected the afterglow in imaging started 90 minutes after the trigger. At that time the OC had H=12.6 +/- 0.15, J = 13.1 +/- 0.23 (GCN 10194). The GROND imager also detected the afterglow, with magnitudes reported below. These were obtained simultaneously in images taken 58 minutes after the trigger: g = 16.63 +- 0.15 r = 16.53 +- 0.15 i = 16.42 +- 0.15 z = 16.35 +- 0.15 J = 16.40 +- 0.10 H = 16.36 +- 0.14 This burst was quite bright and very slow to decays, so it was seen by numerous ground observers in the hours following the trigger. A set of observations showing this decay was obtained using the TAROT at La Silla (GCN 10200): ----------------------------------- Tstart Tstop Rmag (min) (min) ----------------------------------- 69.12 - 82.19 16.4 +/- 0.2 106.59 - 119.67 16.7 +/- 0.3 144.33 - 157.41 16.7 +/- 0.3 182.09 - 222.83 17.0 +/- 0.2 229.91 - 346.22 17.1 +/- 0.2 367.71 - 444.61 17.4 +/- 0.2 ----------------------------------- A spectrum of the object was obtained using the Gemini North telescope in Hawaii. These were two exposures of 90 seconds duration each. The wavelength range of the spectra was 4000 to 8000 angstrom. The spectra were mostly featureless, but two emission lines were seen. They were identified as [OIII] 4959,5007 at a redshift of z = 0.490 (GCN 10202). Additional followup observations from the NOT taken 22.4347 hours after the trigger show the afterglow at R=18.95 (GCN 10205), but observations taken from TAROT at 1.12 and 1.37 days, respectively, do not show any sign of it to R = 20.0 (GCN 10208), Radio observations were also made of the field. The first were from LABOCA/APEX in Chile at 870 um. These began 3.48 hours after the trigger and continued for ~3 hours. In an image with an rms of 4.5mJy, no candidate source is detected (GCN 10206). Observations were also made using the VLA in New Mexico, USA. The 8.46 GHz band was used for two sets of observations taken on November 29.22 and 30.21, respectively. No source was detected to 3-sigma limits of 300 uJy. No deeper observations were done due to the presence of a bright double-radio source nearby (GCN 10211)." GRB 091126 05:33:00 -19:18:00 222.49 -25.63 Lepus 2009/11/26 07:59:24.76 Fermi 0 This burst had a single pulse with a duration of 0.3 seconds. The spectrum was fit by a power-law with exponential cutoff: index = -0.60 +0.24/-0.21, Epeak = 458 +215/-107 keV. GRB 091123 19:48:00 -29:12:00 11.23 -24.35 Sagittarius 2009/11/23 07:08:37.26 Fermi 0 This burst was extremely unusual. The GBM light curve showed four emission peaks separated by long quiet periods. However, comparison with Konus-Wind data showed that the burst was already occurring when its position rose above the limb of the Earth as seen from Fermi. Using only the GBM data the burst duration was 650 seconds. It’s spectrum was fit by a power-law with exponential cutoff: index = -1.-8 +/- 0.05, Epeak = 101.30 +5.16/-4.52 keV. GRB 091120 15:59:00 -24:48:00 348.22 21.15 Scorpius 2009/11/20 04:34:40.23 Fermi 0 "This burst had multiple peaks and lasted about 52 seconds. The spectrum was fit by a power law function with exponential cutoff. The power law index was -1.17 +/- 0.02, with cutoff at Epeak = 129 +.- 3 keV. A Band function fit the spectrum equally well (GCN 10187). This object was also detected as a hard x-ray transient by the Gas Slit Camera (GSC) on the MAXI mission. The position is consistent with the GBM position, though MAXI positions should be improved after the spacecraft completes its commissioning phase (GCN 10188)." GRB 091117 02:03:46.9 -16:56:38 185.33 -70.42 Cetus 2009/11/17 17:44:29 Suzaku none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb091127.jpg "This burst was first noticed by the WAM aboard Suzaku. It was also seen by Konus-Wind, INTEGRAL SPI ACS and the Swift BAT (from which the position has been determined). The BAT saw a weak precursor lasting about 0.12 seconds with the main burst following and lasting about 0.4 seconds. Observations taken with the Swift XRT found an x-ray source coincident with a DSS galaxy (GCN 10173). From the ground, imaging with the 6.5 meter Magellan telescope at Las Campanas, Chile, found that the DSS galaxy was a face-on spiral. A bright point source was seen in one of the spiral arms (GCN 10174), but subsequent spectroscopy from the Gemini-North telescope found that object to have a spectrum consistent with it being an HII region (GCN 10176). Additional observations from Gemini-South in g’, r’ and I’ in poor seeing conditions did not reveal any point sources within the BAT error circle (GCN 10178), or did additional observations from the Magellan telescope in r (GCN 10183)." GRB 091112A 17:10:54 -36:42:54 349.49 1.74 Scorpius 2009/11/12 17:41:21 Swift None has been reported. The light curve for this burst was symmetrical, with a total duration of about 20 seconds. Swift was not able to slew immediately to this burst because of a sun constraint. And since the constraint will not be lifted in the near future, no XRT/UVOT data will be available for this burst. The burst is only 10 degrees from the Galactic center, so it is not possible to rule out the possibility that the burst was caused by a galactic source This burst also triggered the Fermi GBM. The GBM light curve showed a broad peak lasting about 40 seconds. The spectrum was fit by a power-law with index -1.13 +/- 0.04 and a high energy cutoff at Epeak = 750 +/- 120 keV. GRB 091111 09:11:15 -45:54:33 268.15 1.56 Vela 2009/11/11 15:21:59 INTEGRAL 0 This was a low significance trigger, so no automatic alert was sent. The burst was discovered during off-line analysis of the data. The announcement notes that the object has a low galactic latitude, and as a result they cannot rule out the possibility that this is a galactic transient rather than a GRB. GRB 091109B 07:30:56.65 -54:05:23.4 265.93 -16.25 Carina 2009/11/09 21:49:03 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091109b.jpg "This burst showed only a single spike in the BAT light curve. It lasted 0.4 seconds. The XRT began observing the field about 78 seconds after the trigger, finding an uncatalogued x-ray source within the BAT error circle. No OC was found by UVOT in a 250 second U-filter exposure started 296 seconds after the trigger. Observations from the GROND imager on the 2.2 meter telescope at La Silla were able to detect an optical afterglow in images taken 19.1 hours after the burst and continuing for 1.8 hours. These observations are listed beow: g' = 24.5 +/- 0.1 r' = 23.6 +/- 0.1 i' = 23.4 +/- 0.1 z' = 23.3 +/- 0.2 J > 22.2 H > 21.8 K > 21.2 Assuming the g’-r’ color is caused by Lyman alpha absorption allows a photometric redshift of z_p = 3.5 +/- 0.4. Spectroscopy from the VLT/FORS2 taken 21.5 hours after the burst shows a broad absorption at 5700 angstrom. If this is due to Lyman alpha, then the redshift is indeed z = 3.5. However, there is a possible host galaxy at z = 0.44 which could also be responsible for the observed absorption features. Without addition features it is not possible to determine which of these possibilities is correct (GCN 10158)." GRB 091109A 20:37:01.81 -44:09:29.6 356.49 -36.98 Microscopium 2009/11/09 04:57:43 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091109a.jpg "This light curve for this burst had a spiky structure and lasted about 25 seconds. The satellite slewed immediately and began observations with the XRT after 151 seconds and with the UVOT after 155 seconds. The XRT showed a fading, uncatalogued x-ray source within the BAT error circle. The UVOT also found a counterpart. It had unfiltered magnitude of m=19.92 based on the initial 150 second long finder chart exposure. The 60 cm REM telescope at La Silla began observing the field about 77 seconds after the trigger. A faint object was found within the XRT error circle. It had a magnitude of H~14.8 (GCN 10139). The afterglow was also detected by the Faulkes Telescope South. They report I’=21.7 +/- 0.3 and R=21.95 +/- 0.25. The observations were begun 4.74 and 5.29 hours after the trigger, respectively (GCN 10142). " GRB 091104 13:55:01.50 47:24:37.9 95.59 66.2 Canes Venatici 2009/11/04 08:49:22 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/grb091104.jpg This was a BAT image trigger, so no variation was evident in the light curve. The satellite slewed immediately and started observing with the XRT 131.5 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the field, but no OC was found. GRB 091102 04:50:27.87 -72:31:10.9 284.53 -34.72 Mensa 2009/11/02 14:34:38 Swift 0 "This burst showed a multi-peaked structure and had a duration of approximately 10 seconds. Swift was not able to slew immediately because of an observing constraint. As a result, there was no prompt XRT or UVOT data. Starting 985 seconds after the burst, the UVOT aboard Swift obtained a white light finding chart exposure of 150 seconds. No OC was detected (GCN 10118). The XRT obtained 289 seconds of data on the field and found a possible x-ray counterpart close to the BAT position (GCN 10120). Subsequent observations with the XRT comprising a total of 1500 seconds of exposure showed a sharp drop in brightness after 1300 seconds. The power-law decay index was 2.9 +/- 0.6. The GBM aboard Fermi also triggered on this burst. The GBM light curve showed two peaks and a total duration of about 7 seconds (GCN 10126)." GRB 091031 04:42:00 -59:06:00 268.73 -39.49 Dorado 2009/10/31 12:00:28 Fermi 0 The GGM light curve showed many pulses with substructure. The duration of the burst was about 35 seconds. The spectrum was best fit by a Band function with alpha = -0.91 +/- 0.04, beta = -2.34 +0.19/-0.31 and Epeak = 503.10 +47.30/-46.60 keV. GRB 091030 17:40:12 21:32:00 45.47 24.87 Hercules 2009/10/30 19:52:26.86 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/grb091102.jpg The GBM showed two bright peaks followed by two dimmer ones. The burst duration was 160 seconds. The spectrum was fit by a Band function with alpha = -0.88 +/- 0.02, beta = -2.2 +/- 0.1 and Epeak = 507 +/- 30 keV. GRB 091029A 04:00:42.58 -55:57:20.0 266.83 -45.69 Reticulum 2009/10/29 03:53:22 Swift 0 2.752 "The BAT light curve for this burst had a double-peaked structure. It lasted 50 seconds. The XRT began observing the burst 79 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. In an unfiltered finder chart exposure of 150 seconds started 90 seconds after the trigger, the UVOT detected an afterglow candidate within the XRT error circle. The OC magnitude was approximately m = 20.31. Observations were made with the GROND multiband imager from La Sill starting 4.5 minutes after the trigger. A source with g’ = 17.72 +/- 0.1, r’ = 17.45 +/- 01 and J = 17.00 +/- 0.08 was found within the Swift/XRT error circle (GCN 10098). The OC was also detected by three of the six PROMT telescopes at Cerro Tololo in Chile. Observations begun 46 seconds after the trigger detected in BR and I. The afterglow peaked in brightness between 5 to 6 minutes after the trigger, and then faded with a power-law index of -0.5 (GCN 10099). The Gemini-South telescope was used to obtain a spectrum of the object approximately 2 hours after the trigger. The600 seconds exposure GMOS spectrum covered the range from 3900 to 8100 angstroms. Absorption was detected from Lyman alpha, C II, C IV, Si II and Si IV, all at a common redshift of 2.752 (GCN 10100)." GRB 091026A 18:26:217.41 -86:06:41.5 307.27 -26.69 Octans 2009/10/26 13:11:30 Swift http://grb.sonoma.edu/images/swift_bursts/grb091026.jpg This burst had a FRED pulse lasting approximately 20 seconds. The XRT began observing the field 78.7 seconds after the trigger, finding a bright, uncatalogued source within the BAT error circle. No credible OC was found in the initial 150 second unfiltered UVOT data. The field was observed using the GROND multi-band imager on the ESO 2.2 meter telescope at La Silla. The observations began 11.6 hours after the trigger. No OC was detected in any of the filters. Upper limits are listed below (GCN 10091): g' > 24.8 mag, r' > 24.2 mag, i' > 23.9 mag, z' > 23.7 mag, J > 22.2 mag, H > 21.3 mag and K > 20.2 mag. GRB 091024A 22:36:59.7 56:53:23.4 105.33 -1.31 Lacerta 2009/10/24 08:56:01 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091024.jpg 1.092 "This burst had two peaks, with the first occurring at T0 and the second, smaller one, at T+40 seconds. The total duration for the burst was about 50 seconds. Observing constraints prevented Swift from slewing until T+50 seconds, so no prompt XRT or UVOT data was obtained. On the ground, the 2 meter Faulkes Telescope North began observing the BAT field 3.27 minutes after the trigger. An uncatalogued OC was seen with R = 18.1 (GCN 10063). Observations taken with the Global-rent-a-scope in New Mexico detected an m = 18.2+/-0.4 object at the same position as the Faulkes result. The observations were begun 48 minutes after the trigger, and the detection was made in a 600 second unfiltered exposure (GCN 10064). The Gemini North telescope observed the OC with the GMOS-N spectrograph beginning ~1:45 after the trigger. The spectrum covered the range from 5925 to 10200 angstrom and showed absorption from Ca II H&K, Mg I (2853), all at a common redshift of z = 1.092 (GCN 10065)." GRB 091020 11:42:55.18 50:58:41.9 146.9 62.84 Ursa Major 2009/10/20 21:36:44 Swift Optical counterpart at m ~ 15.73 http://grb.sonoma.edu/images/swift_bursts/grb091020.jpg "This burst lasted about 45 seconds. There was an initial bright peak followed by a dimmer one at T+30. The satellite slewed immediately and began observing with the XRT 81 seconds after the trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. In addition, the UVOT found an optical counterpart in its initial 150 second white light exposure, begun at T+89 seconds. The estimated magnitude of the OC was m = 15.73. Ground-based observations from Kislovodsk, Russia also detected the OC. In observations begun 57 minutes after the trigger, a m = 17.5 object was found at the UVOT position. Continuing observations over the subsequent 2.5 hours showed that the source dimmed according to a power-law decay with index alpha = -1.3 (GCN 10052). Additional observations were obtained using the 1.34 meter telescope at Theuringer Landessternwarte Tuatenberg, Germany. The observations began 4 hours after the burst, and are summarized in the table below (GCN 10076): dt Filter mag dmag ____________________________________ 0.166947 Z 18.17 0.13 0.170987 Z 18.10 0.13 0.175038 Z 18.16 0.13 0.179181 Ic 18.45 0.06 0.183221 Ic 18.30 0.05 0.187260 Ic 18.32 0.05 0.191404 Rc 19.43 0.04 0.195444 Rc 19.40 0.04 0.199483 Rc 19.40 0.04 0.203627 V 19.90 0.10 0.207666 V 20.00 0.10 0.211706 V 20.06 0.10 0.215849 B 20.78 0.10 0.219889 B 20.71 0.08 0.223928 B 20.72 0.08 Observations from the NOT/ALFOSC showed that the source had dimmed to R ~ 20 by about T+7.5 hours. Low-resolution spectroscopy covering 3500-9100 angstrom was carried out using the telescope. Absorption from FeII (2344, 2374, 2382), Al III (1854, 1862), Mg II (2798) all at z = 1.71 (Mg II 2803 was blended with atmospheric A-band). Flux is detected down to 3800 angstrom, which sets an upper limit of z < 2.13 for the GRB (GCN 10053). Observations collected using the VLA radio telescope near Socorro, NM have detected the afterglow at 8.46 GHz. Observations were obtained at six different times, with fluxes given below (GCN 10088): Date Flux Density (uJy) Oct 21.66 108 +/- 25 Oct 22.54 108 +/- 25 Oct 22.77 108 +/- 25 Oct 22.99 108 +/- 25 Oct 24.60 230 +/- 42 Oct 26.71 436 +/- 42" GRB 091018A 02:08:44.61 -57:32:53.8 284.08 -56.66 Eridanus 2009/10/18 20:48:19 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb091018.jpg 0.971 "This burst had a single FRED-like light curve lasting about 10 seconds. The XRT began observing the field about 61 seconds after the trigger, finding a bright uncatalogued x-ray source. The UVOT also observed the field, finding a bright, m=14.60 (unfiltered) object in a 150 second long image begun 68 seconds post-trigger. The ROTSE-III telescope on Mt. Gamsberg, Namibia, observed this field about ten minutes after the trigger. An uncatalogued object with m=15.4 was found. The source was rapidly fading, confirming it to the the afterglow of the GRB (GCN 10035). The multiband GROND imager also obtained images of the OC approximately 4 hours after the trigger. These provided the following magnitudes (GCN 10039): g'= 19.061 +/- 0.010 r'= 18.853 +/- 0.007 i'= 18.732 +/- 0.013 z'= 18.70 +/- 0.10 J = 18.3 +/- 0.1 H = 18.2 +/- 0.1 K = 17.9 +/- 0.1 Observations from the Magellan Clay Telescope/MagE eschellette spectrograph provided a spectrum with strong absorption features. These include Mg II, Fe II, Mn II, all at a redshift of z = 0.971 (GCN 10038). Additional spectroscopy was obtained using the VLT/X-shooter. These covered the spectral range from 3000 to 24800 angstroms. Absorption lines were detected from Al II(1670), Al III (1854, 1862), FeII (2260, 2344, 2374, 2382, 2586, 2600), Mn II (2576, 2594, 2606), Mg II (2797, 2803), Mg I (2852) and Ca II(3394, 3969), all at a redshift of z = 0.971, confirming the Magellan result, above. They also report tentative detection of [OII], [OIII] and H-alpha in emission (presumably from the host galaxy) at the same redshift (GCN 10042)." GRB 091015 20:24:31 -06:10:12 38.15 -23.49 Aquila 2009/10/15 23:00:17 INTEGRAL 0 "This was a very long GRB, lasting about 100 seconds. It had a soft spectrum, detected only in the 20-40 keV band. Because the trigger had a low significance, no automatic alert was sent out for this burst, so no prompt followup observations were made. Optical observations obtained with the RTT 1.5 meter telescope at TUBITAK National Observatory in Turkey did not find any optical counterpart to R ~ 22. The observations were undertaken about 18 hours after the trigger (GCN 10029)." GRB 091010 19:54:39.72 -22:31:05.7 18.66 -23.49 Sagittarius 2009/10/10 02:43:09 SuperAGILE 0 "This burst had a lot of structure in its light curve. Its duration was about 10 seconds. Swift began observing the burst about twelve hours after the trigger. A single uncatalogued x-ray source was detected by the XRT within the SuperAGILE error box. It was not clear from these observations if this source was fading (GCN 10006). Observations were carried out with the UVOT simultaneous to the XRT observations. No optical candidate was found to limiting magnitude wh > 21.36 (GCN 10007). The burst was also detected by RXTE. Two flares were seen, the first coincided with the SuperAGILE trigger, the other occurred 2 seconds later. There was also evidence for a weaker flare 5 seconds after the trigger (GCN 10014). Observers using the GROND multi-band imager and the ESO 2.5 meter telescope at La Silla began observing the field about 21 hours after the burst. They found a single faint source with r’ = 22.2 within the XRT error circle. Atmospheric conditions prevented the detection of this source in other bands (GCN 10008)." GRB 091003A 16:46:04.687 36:37:30.76 59.36 40.06 Hercules 2009/10/03 04:35:45.58 Fermi Object seen at r = 21.33 "This burst had multiple peaks. It lasted approximately 21 seconds. The spectrum was fit by a Band function with alpha = -1.13 +/- 0.01, beta = -2.64 +/- 0.24 and Epeak = 486.2 +/- 23.6 keV. The burst was bright enough to cause a Fermi spacecraft repointing maneuver, and 5 hours of pointed observations were made. The LAT showed a significant increase in emission after the GBM trigger (GCN 9985). Observations with the Swift XRT were begun 15.5 hours after the Fermi/GBM trigger. A total of 2.5 kiloseconds were observed, revealing an uncatalogued x-ray source 6.85 arcminutes from the LAT position (GCN 9986). Subsequent observations taken up to 168 kiloseconds after the trigger showed that this source was fading, and thus was the GRB afterglow (GCN 9991). The Swift UVOT observed the source contemporaneously with the XRT. In the initial set of observations a faint, fading source was found inside the XRT error circle. The observations were taken in the uvw2 filter, and the object’s magnitude was 21.02 +/- 0.27. No extinction correction has been applied (GCN 9987). The afterglow was also seen by observers using the William Herschel Telescope and ACAM. In 60 and 250 second exposures started 1.69 days after the trigger, an r = 21.33 _/- 0.11 object was detected. A spectrum was also taken, but only faint continuum emission was seen. No strong or absorption lines were present, but the continuum seen at 4000A implies an upper limit of z = 2.3 for the redshift (GCN 9995)." score GRB 090929B 07:50:52.84 -00:39:29.5 220.43 12.89 Monoceros 2009/09/29 10:09:07 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090929b.jpg "The BAT light curve for this burst has a complex structure with multiple peaks from T-10 seconds to T+50 seconds. Additional weaker peaks are seen at T+150 seconds, with the peak count rate occurring approximately 40 seconds after the trigger. The satellite slewed immediately to the burst and began XRT observations 84 seconds after the trigger. A bright, uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the field starting 93 seconds after the trigger. In a 97 second unfiltered exposure there is not OC found. Observations from the RAPTOR telescope began at 10:20:53.37, 11.77 minutes after the trigger. An object of magnitude R~18.0 was found. A nearby 11th magnitude star hindered attempts to do accurate photometric measurements (GCN 9967). " GRB 090929A 03:45:57.9 -05:57:50 193.97 -43.48 Eridanus 2009/09/29 04:33:03.97 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/grb090929a.jpg "The GBM light curve showed multiple short peaks, with the burst lasting a total of about 8.5 seconds. The spectrum was fit by a power law with exponential cutoff: index = -0.52 +/- 0.06, Epeak = 610.9 +/- 44.5 keV. This burst was also seen by the Swift/BAT instrument during a preplanned slew of the satellite. The BAT light curve had three successively weaker peaks. They occurred at T+1 second, T+4 seconds and T+8 seconds. The duration measured by the BAT was about 10 seconds, with the burst commencing at 04:33:08 UT." GRB 090927 22:55:53.50 -70:58:49.2 315.41 -43.24 Indus 2009/09/27 10:07:16 Fermi http://grb.sonoma.edu/images/swift_bursts/grb090927.jpg 1.37 "This was a short burst, lasting only about 1.5 seconds. It had a single peak. An observing constraint prevented the satellite from slewing to the burst for 33 minutes, so no prompt XRT/UVOT data was obtained. The UVOT began observing the field beginning 2141 seconds (~70 minutes) after the trigger. In a 150 second finder chart exposure (unfiltered) there is an afterglow candidate with m = 19.10 +/- 0.15 (GCN 9946). Images were also obtained from the 1 meter Zadko telescope which showed a fading source within the XRT error circle 110 minutes after the trigger. Magnitudes were measured as follows GCN 9956): tmid(min) Exp. Time R Magnitude ------------------------------------- 110 42s >16 126 540s 19.8 +/- 0.5 158 360s 20.0 +/- 0.5 The VLT/FORS2 was used to obtain a spectrum of the OC starting 16.5 hours after the trigger. At that time the OC had a magnitude of R = 21.7. The spectrum shows absorption from Mg II and Fe II at z = 1.37. No evidence was seen for higher redshift systems, nor for Lyman-alpha, indicating that this is indeed the redshift of the GRB (GCN 9958). " GRB 090926B 03:05:13.66 -39:00:19.6 244.63 -59.78 Fornax 2009/09/26 21:55:48 Swift An object was seen at R = 23, but it was not clear if this was the OC or the GRB host galaxy. http://grb.sonoma.edu/images/swift_bursts/grb090926b.jpg 1.24 "The BAT light curve for this burst had a single pulse lasting about 20 seconds. The XRT began observing this field 88 seconds after the BAT trigger. A bright, fading, uncatalogued x-ray source was found within the BAT error circle. In a 150 second finder chart exposure from the UVOT taken starting 98 seconds after the trigger, no creditable OC was found. This burst was also detected by the Gas Slit Camera aboard the MAXI mission aboard the ISS. A bright x-ray source was seen to turn on at 21:55:31 and stay on until 21:55:55. The source position was consistent with the GRB position reported from Swift. Note that the start time of the x-rays was 17 seconds before the trigger, but roughly consistent with the refined BAT analysis (GCN 9939) reported later (GCN 9943). Observers using NOT report observations of the field in R and I beginning about 5 hours after the trigger. No object is seen within the XRT error circle to a magnitude limit of R ~ 23 (GCN 9941). At the VLT in Chile, observers reported finding a faint, diffuse object within the XRT error circle. The object had a magnitude of R = 23 and was coincident with a faint nebulosity in the NOT images (GCN 9944). Using the FORS2 spectrograph the VLT observers obtained a redshift based upon an emission line taken to be O II 372, and absorption from Mg II, Fe II and Al III, all at z = 1.24. It was not clear if the object measured was the OC itself or some combination of the GRB afterglow and host galaxy (GCN 9947). " GRB 090926A 23:33:36.18 -66:19:25.9 314.69 -48.99 Tucana 2009/09/26 04:20:26.99 Fermi 0 2.1062 "This burst had a single pulse lasting about 20 seconds. The spectrum was fit by a Band function with alpha = -0.75 +/- 0.01, beta = -2.59 +0.04/-0.05, and Epeak = 314 +/- 4 keV. The burst was bright enough to initiate a spacecraft repointing maneuver. It was also detected independently by INTEGRAL. This burst occurred at the edge of the LAT field, and that instrument also detected the burst. The LAT observed GeV photons coming from the burst for more than 200 seconds after the trigger (GCN 9934). The Swift UVOT observed the field beginning 13 hours after the burst. They find an m = 18.78 +/- 0.04 object. The burst was also observed with the XRT (GCN 9936). Observers using the PROMPT telescopes at Cerro Tololo in Chile reported detecting the optical afterglow. In images collected approximately 19 hours after the burst, the measured the following magnitudes (GCN 9937): mean time since cal. trig. tel. exp. fil. magnitude stars (h) (# x s) 19.9 PROMPT-2 22 x 80 V 18.81 +0.10 -0.09 52 NOMAD 20.0 PROMPT-5 22 x 80 I 18.24 +0.04 -0.04 165 USNO B1 20.0 PROMPT-4 24 x 80 R 18.06 +0.03 -0.03 230 USNO B1 A redshift was obtained for this afterglow from the VLT/X-shooter. These observations, which where done a part of the science verification for the new X-shooter single object spectrograph, were begun 22 hours after the burst. The afterglow had R = 17.9 at that time, and four 1800 second exposures were taken to produce the spectra. The final spectrum contained many absorption features, including CIV 1548 and 1550, Si II 1304 and 1526, Si II* 1533, FeII 1608, MgII 2798 and 2803 and unspecified others. There was also a broad absorption near 3780 which was interpreted as damped Lyman-alpha. These lines are all seen at a common redshift of z = 2.1062. The wavelength solution for these lines is based on archival calibration data, so minor corrections might be needed (GCN 9942). score GRB 090925 22:13:00 14:18:00 75.13 -33.49 Pegasus 2009/09/25 09:20:33.67 Fermi 0 This burst had a FRED-like light curve that lasted about 50 seconds. The spectrum was fit by a Band function with alpha = -0.60 +0.14 / - 0.13, beta = -1.91 +0.07 / - 0.09 and Epeak = 156 +25 / -20 keV. GRB 090922A 01:08:00 74:18:00 124.07 11.46 Cassiopeia 2009/09/22 12:56:42.14 Fermi 0 "The main pulse of this burst lasted 10 seconds, and it was followed by a weaker pulse approximately 60 seconds later. The total burst duration was about 92 seconds. The time-averaged spectrum was fit by a Band function with alpha = -0.77 +/- 0.05, beta = -2.28 +/- 0.07 and Epeak = 139.3 +/- 6.6 keV. This burst was 19 degrees from the LAT boresight, and it was bright enough that the spacecraft repositioned itself to better observe with the LAT… results of those observations are not yet reported. " GRB 090916 08:26:19 25:56:00 197.7 31.42 Cancer 2009/09/16 07:00:44 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090916.jpg This burst had a single peak with a duration of 0.4 seconds. The satellite did not slew to the burst because of a Moon constraint. The XRT did observe the field starting 9.3 hours after the trigger. At that time, 12.3ks of exposure did not reveal any x-ray source within the BAT error circle (GCN 9925). GRB 090915 15:52:04.85 15:29:15.9 26.9 46.6 Serpens 2009/09/15 15:35:36 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090915.jpg "This burst was week and only discovered during ground analysis. It was possibly the same event as the Fermi GBM trigger 274721737. It had a single peak and a duration (T90) of about 8 seconds. The Swift XRT began observing the field 12.4 hours after the trigger. A fading source was found in 5ks of exposures (GCN 9914). From the ground, the 0.9 meter SARA telescope at Kitt Peak observed the field starting ~12.3 hours after the burst. Observations continued for about half an hour. In 21 minutes of stacked exposures a marginal source was detected within the XRT error circle. The magnitude is R ~ 20.5 +/- 0.3 (compared to USNO B1.0 field stars). The object is not present in the DSS (9920)." GRB 090912 12:32:10.13 61:29:04.4 126.99 55.49 Ursa Major 2009/09/12 15:50:29 Swift 0 "This burst had a duration of about 130 seconds. It had a pulse that occurred at T+0 seconds and another at T+90 seconds. The XRT about 793 seconds after the burst. An uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the field, but found no creditable optical counterpart to the GRB. The x-ray afterglow had disappeared in XRT observations taken 13 and 17 days later, respectively. Thus the XRT source reported initially was likely the afterglow of the GRB (GCN 9911). Optical limits were obtained from the ground using 0.4 meter telescope at Hankasalmi Observatory. In a series of 57 stacked images of 1 minute duration each, no OC is seen to a limit of 21.6 (unfiltered). USNO-A2.0 stars were used for magnitude comparison, and the midpoint of the exposure series occurred on Sept 12 19:33 UT (GCN 9907)." GRB 090910 19:44:00 72:18:00 104.32 21.89 Draco 2009/09/10 19:29:48.81 Fermi 0 The burst had 3 pulses between T0-5 seconds to T0-45 seconds. A smaller pulse was seen at T0+70 seconds. The duration (T90) was 62 seconds. The spectrum was fit by a Band function with alpha = -0.9 +/- 0.1, beta = -2.0 +/- 0.2 and Epeak = 274.8 +/- 56.1 keV. GRB 090912 17:36:44.50 -25:12:49.7 2.12 3.64 Ophiuchus 2009/09/04 01:24:18 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090912.jpg "This burst showed multiple overlapping peaks, the first at T-5 seconds, and continuing for ~60 seconds. The XRT began observing the field at T+134.2 seconds. It found an uncatalogued x-ray source within the BAT error circle. The UVOT did not find any OC in unfiltered exposures started 137 seconds after the trigger. Observations from La Silla using the REM 60 cm telescope started 108 seconds after the trigger. No OC was found in exposures in VRIJHK. The field is quite close to the Galactic center, and so it is quite strongly reddened (and extincted). These observations did reveal an H=11.95 2MASS star at the XRT position (GCN 9892). The field was also observed using the 2.2 meter ESO telescope and GROND multiband imager. The initial observations were begun 4 minutes after the trigger. A second set of observations was obtained 24 hours later. Subtracting the two epochs reveals a faint, fading object, 1.1â€� south/east of the 2MASS object mentioned in GCN 9892. It’s magnitude was r’ ~ 22.2 6.5 minutes after the trigger, and it was seen in all GROND filters except g’. Due to the large Galactic extinction (E(B-V = 1.76) it is not possible to deduce any redshift information from the magnitude information (GCN 9901)." GRB 090904A 06:43:31.58 50:12:14.4 165.6 19.31 Lynx 2009/09/04 01:01:06 Swift none http://grb.sonoma.edu/images/swift_bursts/grb090904a.jpg "The BAT light curve for this burst had a small burst at T=0, then two larger peaks, one at T+130 seconds and the other at T+175 seconds. The total duration for the burst was at least 200 seconds. Observations from the XRT began 271.7 seconds after the trigger, revealing a bright, uncatalogued and fading source within the BAT error circle. The UVOT also observed the field, starting 141 seconds after the trigger, but not all of the image was received. No OC was detected in the data that were received. Imaging from the ground using the ROTSE-III telescope in Turkey placed limiting magnitudes on any source at m > 15.8 at T+84.6 and m > 17.8 at T+221.2 (GCN 9880)." GRB 090904B 17:39:45.26 27:19:28.1 51.5 26.91 Hercules 2009/09/02 11:05:08 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/grb090904b.jpg 1.822 "This burst had a single bright pulse lasting about 21 seconds. It was also independently detected by the INTEGRAL SPI-ACS. The spectrum was fit by a Band function with alpha =-0.696 +/- 0.012, beta = -3.85 +0.21/-0.31 and Epeak = 775 +/- 11 keV. The burst was also seen in the LAT (GCN 9867). Ongoing analysis with the Fermi GBM and LAT showed that the burst was detected in the LAT for at least 300 seconds. The Swift satellite began TOO observations 12.5 hours after the GBM trigger. It found an uncatalogued x-ray source within the GBM error circle (GCN 9868). Analysis of the observations, taken over ~4.5 hours, confirms that the object was fading, and thus was likely the GRB afterglow (GCN 9876). Swift UVOT observations were done simultaneously to the XRT ones, and a faint (m = 20.41 +/- 0.2) object was found within the XRT error circle. Though the object is not visible in the DSS image of the field, there is another faint object nearby, so it was not possible to make a positive identification between the two (GCN 9869). Observations taken with the 1 meter Nickel telescope at Lick Observatory were consistent with the source found by the UVOT, but no fading was evident, so the identification of the source with the GRB was still uncertain (GCN 9870). A spectrum obtained using the Gemini North telescope showed metal absorption from MgII[2796,2803], MgI[2853],MnII[2606], FeII[2600], MnII[2594], FeII[2586], FeII[2260], SiII[1808], SiII*[1816], all at a redshift of z = 1.822 (GCN 9873). This field was observed on September 03.94 from the Very Large Array radio telescope in New Mexico. The GRB was detected at 8.46 GHz (GCN 9889)." score GRB 090902A 19:24:00 53:06:00 84.55 16.8 Cygnus 2009/09/02 09:38:05.49 Fermi 0 This burst had a single peak and lasted approximately 1.2 seconds. The spectrum was fit using a Band function with alpha = 0.30 +0/5/-0.26, beta = -2.05 +0.29/-0.24 and Epeak = 388 +82/-102 keV. GRB 090831C 07:13:10.34 -25:07:09.6 237.75 -6.73 Canis Major 2009/08/31 21:30:25 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090831c.jpg "This burst lasted about 10 seconds. It had a single peak. The XRT began observing the field 117.5 seconds after the trigger. A fading, uncatalogued x-ray source was seen within the BAT error circle. In images starting 120 seconds after the trigger, the UVOT did not detect any OC. Observations were made using the GROND instrument on the 2.2 meter telescope at La Silla. This observations were started 10.6 hours after the trigger, and only faint upper limits were reported: g' > 23.5 r' > 24.0 i' > 23.3 z' > 22.9 J > 21.4 H > 21.1 K > 20.0 GRB 090831B 00:14:29 27:58:12 113.06 -34.19 Andromeda 2009/08/31 18:01:14 Swift 0 "This was an image trigger, and so nothing is seen in the BAT light curve. The XRT started observing the field 149.9 seconds after the BAT trigger. No source was detected in the prompt data downloads. The UVOT also observed the field, beginning 153 seconds after the trigger. No optical source was found. The RIMOTS 30 cm telescope in Miyasaki, Japan was used to observe the Swift position beginning about 2.5 minutes after the trigger. In unfiltered CCD images no source was seen. Upper limits of m = 15.4 (based on USNO-A2.0) were given for the first frame. Fainter limits were obtained by stacking 27 frames taken over nearly 40 minutes thereafter (GCN 9853). Somewhat fainter limits in g’, Rc and Ic were obtained using the MITSuME 50 cm telescope (GCN 9858): #PDAY MID-UT T-EXP g' Rc Ic -------------------------------------------------- 0.00505 18:09:49 540.0 >19.0 >18.8 >18.1 0.03482 18:52:41 4200.0 >19.9 >19.7 >19.0 -------------------------------------------------- " GRB 090831A 09:40:00 51:00:00 166.01 46.9 Ursa Major 2009/08/31 07:36:36.58 Fermi 0 This burst had two structured main peaks. Its total duration was about 69 seconds. The spectrum was fit by a power law with exponential cutoof. The power law index was -1.57 +/- 0.03, and the cutoff energy was Epeak = 399.6 keV. A Band function could also fit the spectrum: alpha = -1.52 +/- 0.06, beta = -1.96 +/-0.14, Epeak = 243.8 +-85.3. GRB 090829B 23:40:00 -09:22:00 76.05 -65.51 Aquarius 2009/08/29 16:50:40.13 Fermi 0 This burst lasted approximately 100 seconds and had two widely separated peaks. The spectrum was fit by a Band function with alpha = -0.7 +/- 0.2, beta = -2.4 +/- 0.5 and Epeak = 143 +/- 30 keV. GRB 090829A 21:57:00 34:11:00 86.5 -16.07 Pegasus 2009/08/29 16:07:38.86 Fermi 0 This burst lasted 85 seconds. It had a weak precursor followed by a single bright peak. The spectrum was fit by a Band function with alpha = -1.44 +/- 0.04, beta = -2.1 +/- 0.1 and Epeak = 183 +/- 31 keV. GRB 090828 08:18:00 -26:06:00 245.95 5.4 Puppis 2009/08/28 02:22:48.20 Fermi 0 This light curve had three pulses with a total duration of ~100 seconds. The spectrum was fit by a Band function with alpha = -1.23 +0.06/-0.05, beta = -2.12 +0.08/-0.11 and Epeak = 136.5 +16.0/-13.7. GRB 090827 01:13:44.4 -50:53:58 294.32 -65.85 Phoenix 2009/08/27 19:06:26 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090827.jpg This burst did not cause an on-board trigger. Instead, it was found during ground analysis. It had a single pulse lasting 7 seconds. It was also seen by Konus-Wind and INTEGRAL-SPI-ACS. GRB 090826 09:22:00 -00:06:00 232.41 32.87 Hydra 2009/08/26 01:37:31.85 Fermi 0 The burst had two pulses with a total duration of approximately 8.5 seconds. The spectrum was fit using a power law with exponential cutoff. The power law index was -0.96 +0.32/-0.28. The cutoff energy was Epeak = 172 +132/-64 keV. GRB 090823 15:14:50.6 60:39:36 97.17 48.67 Draco 2009/08/23 16:11:12 Suzaku 0 http://grb.sonoma.edu/images/swift_bursts/grb090823.jpg "This burst triggered the WAM instrument aboard Suzaku. It was also observed by Konus-Wind, AGILE-MCAL and the Swift-BAT (during a slew maneuver). IPN triangulation confirmed the BAT position. The burst had two peaks at, T+1 and T+4 seconds, respectively. Emission was seen above 700 keV, but none was seen above 1.4 MeV. The total burst duration was approximately 20 seconds, though the Swift-BAT data does not begin until ~T+10.5 seconds. " GRB 090820B 21:13:00 -18:36:00 30.44 -39.34 Capricornus 2009/08/20 12:13:16.70 Fermi 0 The light curve had two narrow peaks and a duration of about 11.2 seconds. The spectrum was fit by a power law with exponential cutoff. The power law index was -1.44 +/- 0.18, with cutoff energy 38.8 +/- 4.4 keV. GRB 090820A 05:51:00 27:00:00 182.27 0.02 Taurus 2009/08/20 00:38:16.19 Fermi 0 "This burst had a weak precursor, then, 30 seconds later, a bright pulse that lasted 30 seconds. The spectrum was fit by a Band function with alpha = -0.69 +/- 0.01, beta = -2.61 +/- 0.05 and Epeak = 215 +/- 3 keV. The burst was so bright that Fermi repositioned to do a pointed observation beginning 3100 seconds after the trigger. Earth constraint prevented an earlier pointed observation. This burst was also detected by the RT-2 Experiment (both detectors RT-2/S and RT-2/G) aboard CORONAS-PHOTON. A precursor followed by single peak at T0+34 seconds was seen, consistent with the behavior seen by Fermi. The burst width was seen to diminish with increasing energy (GCN 9833)." GRB 090817 04:15:51.8 44:07:44.5 157.03 -4.8 Perseus 2009/08/17 00:51:33 INTEGRAL "This burst had a long duration, 240 seconds, and two prominent peaks, one at the beginning and one near the end. The Swift-XRT observed the field starting 3 hours after the trigger until nearly 5 hours after, obtaining a total of 30 minutes of data on-target. An uncatalogued x-ray source was found in the INTEGRAL error circle. This source was 1.3 arcseconds from the USNO-B1 source, which has magnitudes I = 18.5, R = 20.0 and B = 20.8. The x-ray source showed a rapid rise in brightness followed by dimming. Given this light curve it is not certain that the observed source is the GRB afterglow. Additional observations are planned for 8/17 (GCN 9819). The UVOT also observed the field, but no optical counterpart was seen to m > 21.3." GRB 090815C 04:17:57.6 -65:56:33.5 278.31 -39.91 Reticulum 2009/08/15 23:21:39 Swift none has been reported. http://grb.sonoma.edu/images/swift_bursts/grb090815c.jpg This burst triggered, the BAT, but the signal was below the threshold for a normal GCN announcement. As a result, no GCN notice was sent out. In addition, Earth observing constraint prevented the spacecraft from slewing automatically. The light curve shows a single weak peak, lasting 0.6 +/- 0.3 seconds. The spectrum was best fit by a simple power law of index 0.90 +/- 0.47. GRB 090815B 01:26:00 53:24:00 128.14 -9.12 Cassiopeia 2009/08/15 10:30:41.85 Fermi 0 This burst had two peaks, lasting a total of 30 seconds. The spectrum was fit by a power law with exponential cutoff at Epeak = 15.1 +/- 10.8 keV. The index was -1.89 +/- 0.12. GRB 090815A 02:47:00 -02:00:00 175.62 -52.62 Eridanus 2009/08/15 07:12:12.45 Fermi 0 This burst was quite long, lasting 200 seconds. It had a single broad pulse. The spectrum was fit by a simple power-law with an index of -1.15 +/- 0.1. GRB 090814C 22:10:00 58:54:00 103.37 2.3 Cepheus 2009/08/14 08:49:41.22 Fermi 0 The GBM light curve had a single peak lasting 0.25 seconds. The spectrum was fit by a power law with exponential cutoff at Epeak = 790 +/- 120 keV. The power law index was -0.39 +/- 0.11. GRB 090814B 04:18:59.7 60:34:46.6 145.87 7.32 Camelopardalis 2009/08/14 01:21:33 INTEGRAL 0 This GRB lasted approximately 50 seconds. GRB 090814A 15:58:26.29 25:37:51.7 41.87 48.34 Serpens 2009/08/14 00:52:18 Swift Counterpart seen at g' = 21.62 http://grb.sonoma.edu/images/swift_bursts/grb090814a.jpg 0.696 "The BAT light curve had a duration of approximately 30 seconds and showed multiple weak peaks over that period. The XRT started observing the field 159 seconds after the trigger; a bright, fading, uncatalogued x-ray source was found. The UVOT also observed the field, but in the 150 second unfiltered image taken 169 seconds after the trigger, no OC was found. From the ground, observers using the GROND multiband imager on the 2.2 meter telescope at La Silla began observing the field 7 minutes after the trigger. They found a single point source within the XRt error circle with g’ = 21.62 +/- 0.04 and r’ = 21.21 +/- 0.04. Only faint upper limits are reported for the other filters (GCN 9794). A spectrum was obtained using the FORS2 spectrograph at the VLT on Paranal in Chile. The spectrum was taken 70 minutes after the burst trigger. The continuum was seen down to at least 3900 Angstrom, and no Lyman-alpha was detected. This places an upper limit of z < 2.2 on the burst. Weak absorption from Mg II and Ca II at z = 0.696 place a lower limit on the redshift. While the Mg and Ca absorption could be intrinsic to the burst itself, it could also be caused by intervening material (GCN 9797)." GRB 090813A 15:08:12.38 88:34:07.3 122.02 28.31 Ursa Minor 2009/08/13 04:10:43 Swift Counterpart seen at I ~ 18. http://grb.sonoma.edu/images/swift_bursts/grb090813.jpg "This burst lasted about 8 seconds. The light curve showed two peaks. The XRT began observing the field 79 seconds after the trigger and found a bright, uncatalogued x-ray source. The UVOT also observed the field, beginning 87 seconds after the burst, but no OC was found. From the ground, observers using the Palomar 60 inch telescope imaged the field in r’, I’ and z’ beginning about 2 minutes after the trigger. A fading point source was found within the the BAT error circle. The magnitude (converted to I-band) is around I = 18 (GCN 9783). Imaging was also done using the Calar Alto 1.23 meter telescope, beginning approximately 4.5 minutes after the trigger. It showed an I ~17 object coinciding with the XRT source, though not present in the DSS plate of the region (GCN 9782). The burst also triggered the Fermi GBM, which saw two separate pulses lasting about 9 seconds total. The spectrum was fit by a power law with high energy cutoff. The power law index was -1.43 +/- 0.08 and the cutoff energy was Epeak = 161 +/- 26 keV (GCN 9792)." GRB 090812A 23:32:48.53 -10:36:17.3 70.93 -65.19 Aquarius 2009/08/12 06:02:08 Swift Counterpart seen at R = 15.98 http://grb.sonoma.edu/images/swift_bursts/grb090812.jpg 2.542 "This burst had a triple-peaked structure and a duration of approximately 70 seconds. The XRT began observing the field 77 seconds after the trigger: A bright, uncatalogued x-ray source was found within the BAT error circle. The UVOT also observed the field, beginning 298 seconds after the trigger. A candidate OC was found with U = 18.62. The optical counterpart of this burst was confirmed by ground-observers. The RAPTOR telescope obtained early-time Cousins VRI photometry, and the OC was seen in all three bands. The R values follow (GCN 9778): t-mid(s) exp(s) mag mag-err -------------------------------------------- 26.48 5.0 15.98 0.18 46.08 5.0 15.39 0.11 73.55 5.0 14.84 0.07 91.71 5.0 15.13 0.09 101.21 5.0 15.25 0.10 141.62 10.0 15.63 0.10 Using the Palomar 60 inch telescope, observers found an object with the following magnitudes (GCN 9769): Time (UT mid-point) Exposure (s) Filter Magnitude ----------------------------------------------------------------------- 06:05:02 60 r' 16.18 06:06:27 60 i' 16.39 06:09:28 60 r' 17.30 06:10:43 60 i' 17.34 Similar results were obtained using the Liverpool Telescope (GCN 9770): Mid Time Delay from BAT Total Exp Filter Mag (UT) trigger (s) (s) ---------------------------------------------------------- 06:03:59 111 10 r' 15.51 +- 0.04 06:06:26 258 10 r' 16.60 +- 0.10 ---------------------------------------------------------- Observers using the VLT in Chile were able to obtain a spectrum and redshift for the object. Based upon absorption from Lyman-alpha, Si II, Si II*, C II, Si IV, C IV, Al II, Al III, Fe II, Zn II, Mn II and Ti II, they report a redshift of z = 2.542 (GCN 9771)." GRB 090809B 06:21:00 00:08:00 209.57 -6.83 Monoceros 2009/08/09 23:28:14.61 Fermi 0 This burst consisted of a single pulse in the GBM. It lasted approximately 15 seconds. The spectrum was fit using a Band function with alpha=-0.85 +/- 0.04, beta = -2.02 +/- 0.06 and Epeak = 198 +/- 13 keV. GRB 090809A 21:54:43.17 -00:05:01.9 57.98 -39.71 Aquarius 2009/08/09 17:31:14 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090809.jpg "This burst lasted approximately ten seconds. It showed only a single weak peak. The satellite slewed immediately to the burst and started XRT observations 104 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. Beginning 107 second post trigger the UVOT also imaged the field. A possible OC was found, with an unfiltered magnitude of m = 19.9. The OC position did not include the XRT position in this initial sub-image. From the ground, observers using the Nordic Optical Telescope confirmed the UVOT candidate as the afterglow. In images obtained 4.3 hours after the burst, they find an I~19.1, R~20.3 object corresponding to the UVOT object but not present in SDSS frames of the same field, strongly suggesting that this is indeed the GRB afterglow (GCN 9755)." GRB 090807B 21:48:00 07:12:00 63.86 -33.9 Pegasus 2009/08/07 19:57:59.02 Fermi 0 This burst had a single pulse with structure. The pulse lasted about 3 seconds. The spectrum was fit by a Band function with alpha = -0.6 +/- 0.4, beta = -2.4 +/- 0.1 and Epeak = 37 +/- 5 keV. GRB 090807A 18:14:58.51 10:15:59.3 38.08 12.71 Ophiuchus 2009/08/07 15:00:27 Swift 0 http://grb.sonoma.edu/images/swift_bursts/grb090807.jpg "This was an image trigger and so the BAT TDRSS does not show a light curve. The XRT began observing the field 154 seconds after the trigger. A bright, fading uncatalogued source was found. The UVOT also observed the field, starting 163 seconds after the trigger, but no OC was found in the initial reductions. The limiting magnitude (3-sigma) was approximately 19.2. Subsequent imaging and analysis with the UVOT failed to find any object consistent with the position of the XRT source to a magnitude fainter than 21.1 in exposures that continued to ~12 minutes after the trigger (GCN 9751). Ground-based observers faired no better than Swift in finding an OC. Early observations from the ground obtained limits consistent with those from the UVOT. The deepest limits were set by the Liverpool Telescope, though their observations did not start until 8 hours after the burst. They found no OC to R > 22.1 and I > 22.0 (GCN 9753). " GRB 090802B 17:48:00 -71:46:00 321.73 -20.92 Apus 2009/08/02 15:58:23.44 Fermi 0 This was a weak source, and no additional information is given. GRB 090802A 03:24:00 37:54:00 153.36 -15.8 Perseus 2009/08/02 05:39:03.08 Fermi 0 The BGM light curve had a single FRED peak lasting 128 milliseconds. The spectrum was fit by a Band function with alpha = -0.42 (-0.17 +0.21), beta = -2.4 (-0.7 +0.3) and Epeak = 283 (-53 +58) keV. GRB 090728A 01:58:36.56 41:37:57.7 136.18 -19.51 Andromeda 2009/07/28 14:45:45 Swift Counterpart seen at I’=19.55 http://grb.sonoma.edu/images/swift_bursts/grb090728.jpg "The BAT light curve for this burst is a single peak that lasted approximately 20 seconds. Swift slewed immediately to this burst and started observing 110 seconds after the trigger. A bright, uncatalogued x-ray source was found. The UVOT also observed the field, starting 116 seconds after the trigger, but no OC was detected. Ground-based observations were reported from the 2 meter Faulkes Telescope North. In a set of observations started 9.6 minutes after the burst trigger, a rapidly fading OC was found. It was not seen in R, but was seen at I’ = 19.55 +/- 0.3 (mean time 13.2 minutes after the trigger). " GRB 090727A 21:03:50.59 64:55:29.3 101.65 11.95 Cepheus 2009/07/27 22:42:18 Swift Counterpart seen at r’=19.4 http://grb.sonoma.edu/images/swift_bursts/grb090727.jpg "This burst had a single peak lasting approximately 25 seconds. The satellite slewed immediately, with the XRT beginning observations 88 seconds after the trigger. An uncatalogued x-ray source was found within the BAT error circle. The UVOT also imaged the field, starting 91 seconds after the trigger. No OC was found in the initial data products. The robotic 2 meter Liverpool Telescope began observing the GRB field approximately 161 seconds after the trigger. A source not present in the DSS was found in r’ and I’ lying within the XRT error circle. The magnitude of the source is reported as R = 21.3 +/- 0.2, I = 20.2 +/- 0.2 (GCN 9719). Subsequent observations and analysis showed that the object exhibited appreciable variability within the first 100 minutes after the burst. A flare was seen to r’ = 19.4, followed by a plateau and a break, similar to the XRT light curve (GCN 9722). The object was also observed from Calar Alto Observatory using the 1.23 meter telescope. It had I = ~19.4 in exposures taken between 0.45 and 1.45 hours after the burst (GCN 9728)." GRB 090726 16:35:16 72:52:15 105.46 35.63 Draco 2009/07/26 22:42:27 Swift R = 17.69 http://grb.sonoma.edu/images/swift_bursts/grb090726.jpg 2.71 "The BAT light curve had a small precursor at T-20 seconds, then a single FRED pulse with rapid variability superimposed. The duration was about 50 seconds. Not prompt UVOT/XRT data were obtained because the satellite could not slew for ~49 minutes. Following the lifting of the Earth-limb constraint, Swift slewed and began observing with the XRT; an uncatalogued was found within the BAT error circle (GCN 9707). No optical counterpart was seen by the UVOT at that time (GCN 9708). From the ground, observers using the 1 meter SAO RAS telescope in the Caucasus, Russia, found an object in the field that faded over time, as follows (GCN 9709): R_mag exp.(sec) mid.time (sec after the trigger) 18.26 +/- 0.05 60 2126 18.39 +/- 0.05 60 2252 18.33 +/- 0.05 60 2344 18.71 +/- 0.05 120 3183 18.97 +/- 0.05 180 4296 19.17 +/- 0.06 180 5492 19.28 +/- 0.07 240 6089 19.55 +/- 0.12 300 6824 A spectrum was obtained using the 6 meter telescope at the same observatory. Lines of Si I (1526.7), CIV (1548.2, 1550.8), Al II (1670.8), Si II (1304.4, 1309.3), Si IV (1393.7, 1402.7), Fe II (1608.4) and Lyman alpha were found, all at a redshift of z = 2.71. The afterglow was also detected at much earlier times, only 194 seconds after the trigger, by observers using the 0.5 meter telescope at Ondrejov, Czech Republic. It had a magnitude of m ~ 18.3 (GCN 9714). Observers in Slovenia at the Crni Vrh Observatory also obtained photometric data shortly after the burst. Their data are below (GCN 9715): Time Mag Err. [s] [R] [1-sigma] ---------------------------------- 153.8 18.44 0.04 224.9 18.35 0.04 296.0 17.86 0.04 367.2 17.69 0.04 438.0 17.68 0.04 508.8 17.75 0.04 579.6 17.82 0.04 650.3 17.76 0.04 721.0 17.76 0.04 791.8 17.83 0.04 862.5 17.71 0.04 933.3 17.83 0.04 1004.0 17.89 0.04 1074.7 18.05 0.04 1146.1 18.17 0.04 1218.2 18.11 0.04 1288.9 18.00 0.04 1359.6 18.02 0.04 1430.5 18.16 0.04 1501.5 17.96 0.04 " GRB 090720B 13:32:00 -54:48:00 308.81 7.61 Centaurus 2009/07/20 17:02:56.910 Fermi 0 This GRB had two bright peaks. It lasted about 20 seconds. The spectrum was fit by a power-law with exponential cutoff: index =-1.01 +/- 0.5, Epeak = 982 +/- 186 keV. It could be fit equally well using a Band function with alpha = -1.00 +/- 0.05, beta = -2.43 +/- 0.47 and Epeak = 924 +/- 201 keV. GRB 090720 13:18:00 -16:24:00 312.12 46 Virgo 2009/07/20 06:38:08.28 Fermi 0 http://grb.sonoma.edu/images/swift_bursts/grb090720.jpg The light curve for this burst had a single peak lasting about 7 seconds. The spectrum for this burst was fit by a power law with exponential cutoff: index = -0.75 +/- 0.10, Epeak = 117.5 +/- 7.12. GRB 090719 22:45:00 -67:52:00 319.17 -45.07 Indus 2009/07/19 01:31:26.61 Fermi 0 The GBM light curve had a bright pulse with substructure and a duration of approximately 16 seconds. The spectrum was fit by a Band function with alpha = -0.68 +/- 0.02, beta = -2.92 +/- 0.16 and Epeak = 254 +/- 6 keV. GRB 090718B 18:16:00 -36:23:00 356.63 -9.21 Sagittarius 2009/07/18 18:17:42.84 Fermi 0 The light curve had a total duration of approximately 28 seconds and exhibited several peaks. The spectrum was fit by a power law with exponential cutoff. The power law index is -1.21 +/- 0.02 and the cutoff energy is Epeak = 198 +/- 9 keV. A Band function also fits the spectrum: alpha = -1.18 +/- 0.03, beta = -2.59 +/- 0.26 and Epeak = 184 +/- 9 keV. GRB 090718A 16:10:00 -06:35:00 5.35 31.35 Ophiuchus 2009/07/18 17:16:42.93 Fermi 0 This was a weak source, and no additional information is available. GRB 090717B 16:28:00 23:00:00 40.71 41.15 Hercules 2009/07/17 02:40:31.79 Fermi 0 The GBM light curve had a single peak lasting 0.9 seconds. The spectrum was fit by a simple power law with index -1.02 +/- 0.04. GRB 090717A 05:47:00 -64:12:00 273.67 -31.2 Dorado 2009/07/17 00:49:32.11 Fermi 0 The GBM showed two peaks, with a total duration of approximately 70 seconds. The spectrum was fit by a Band function with alpha = -0.88 +/- 0.04, beta = -2.33 +/- 0.06 and Epeak = 120 +/- 5 keV. GRB 090715B 16:45:21.62 44:50:21.3 70.11 40.65 Hercules 2009/07/15 21:03:14 Swift http://grb.sonoma.edu/images/swift_bursts/grb090715b.jpg 3.00 "The BAT showed a multipeaked light curve lasting approximately 100 seconds. Swift slewed immediately to this burst, starting XRT observations 46.2 seconds after the trigger. A bright, uncatalogued x-ray source was found in the BAT error circle. The UVOT took an unfiltered 150 second finder chart exposure beginning 53 seconds after the trigger. A faint object was detected near the XRT source, near the edge of the XRT error circle. The magnitude is estimated to be 20.5 +/- 0.5. From the ground, the 2 meter Liverpool telescope started observing the field 11.07 minutes after the trigger. An object with r’ = 19.6 +/- 0.2 was found at T=11.53 minutes (GCN 9670). The same object was detected with the NOT telescope at R = 19.02 (GCN 9671). The William Herschel Telescope was used to obtain a spectrum of the OC at T~2:45. The spectrum showed absorption lines of Lyman alpha, Lyman beta, Si II, S II and others. The redshift was z = 3.00." GRB 090715A 10:08:29 09:59:50 229.05 48.01 Leo 2009/07/15 17:25:39 Swift http://grb.sonoma.edu/images/swift_bursts/grb090715a.jpg This burst had a single peak and lasted 0.4 seconds. Sun constraint, as well as a problem with the Solid State Recorder (GCN 9664) both prevented Swift from slewing to this burst. Thus, no XRT or UVOT data will be available for this burst. GRB 090713 18:59:00 -03:20:00 30.82 -3.2 Aquila 2009/07/13 00:29:28.06 Fermi 0 This burst had multiple peaks and lasted approximately 113 seconds. The spectrum was fit by a power law with exponential cutoff: index = -0.34 +/- 0.12, Epeak = 99 +/- 5 keV. GRB 090712 04:40:24 22:33:25 176.69 -15.65 Taurus 2009/07/12 03:51:05 Swift none has been reported. This burst lasted ~100 seconds. It had a single broad peak in the BAT light curve. Sun constraint prevented the satellite from slewing to the field. This constraint will be in effect until 21 July, so no XRT/UVOT data will be available for this burst. This burst also triggered the Fermi GBM. GRB 090709B 06:14:22 64:05:07 150.32 20.33 Camelopardalis 2009/07/09 15:07:42 Swift none has been reported. Swift could not slew due to Sun constraint. The constraint will not be lifted until 18 July, 2009, so no prompt XRT/UVOT data will be available. The BAT showed a single peak lasting ~10 seconds. The burst also triggered the Fermi GBM. GRB 090709A 19:19:43 60:43:51 91.82 20.13 Draco 2009/07/09 07:38:34 Swift Counterpart seen at r' = 21.7 "This burst had four major peaks, with the first occurring about 20 seconds before the trigger and continuing for about 100 seconds after the trigger. The satellite slewed immediately to the burst and began observing with the XRT after 68 seconds. A fading, uncatalogued object was found within the BAT error circle. The UVOT began observing 76 seconds after the trigger, but no OC was found in the initial data analysis. From the ground, many telescopes were used to observe the field in the optical, NIR and radio. The first reported optical limits were from the ROTSE-III telescope, which reported limiting magnitudes in the 16 to 18 range in observations begun 30 seconds after the trigger and continuing for ~6 minutes (GCN 9626). At approximately the same time, the Faulkes North telescope set slightly fainter limits in R and I: R > 19.3, I > 18.3 (GCN 9630). The Subaru telescope in Hawaii was used to image the field, and it detected two sources close to the XRT error circle. One had J = 19.0, K = 18.2 and the other K = 18.6 (not seen in J, GCN 9634). The Palomar 60 inch telescope also observed the field, making marginal detections in z’ and r’, but only in two images out of seven (GCN 9646): UT Midpoint Exposure (s) Filter AB Mag ---------------------------------------------------------------------- 7:40:56 60 r' 21.7 +- 0.4 7:45:12 60 r' > 21.4 8:08:57 600 r' > 22.9 7:46:38 60 i' > 21.0 8:11:59 480 i' > 22.8 7:45:55 120 z' 20.5 +- 0.5 8:13:59 480 z' > 21.5 The PARITEL 1.3m telescope on Mt. Hopkins, Arizona was used to obtain images starting ~108 seconds after the trigger. The images, taken in J H and K did not initially show any source to limits consistent with those above (GCN 9628). However, closer inspection of the data did reveal a source in H and K within the XRT error circle. Magnitudes are as follows: post_burst t_mid(s) exp(s) filt mag 438 374 J > 17.7 (3 sig) 438 374 H 16.7 +/- 0.2 438 374 Ks 15.3 +/- 0.2 Images taken later in the night did not show this source, suggesting that it was the OC of the GRB (GCN 9635). Reanalysis of the early Faulkes data also revealed a barely-detected object at the position of the PARITEL source and the second of the two Subaru sources (GCN 9648). Observations taken using the 10.3 meter GTC on La Palma failed to detect the afterglow to I’ = 25.5 approximately 41 hours after the trigger (GCN 9655). In observations taken at Westerbork around the same time, no object was seen at the OC position (GCN 9654), nor did VLA observations detect the OC (GCN 9657)." GRB 090708 10:18:30 26:38:11 204.82 56.03 Leo 2009/07/08 03:38:15 Swift none has been reported. "Swift did not slew to this burst due to Sun constraint. The field will not be available until early October, and so no XRT/UVOT data will be available for this burst. The BAT light curve showed a single peak lasting approximately 20 seconds. The burst also triggered in the Fermi/GBM. The GBM spectrum was fit by a power law with exponential cutoff. The power law index was -1.29 +0.41/-0.34 and the cutoff energy was Epeak = 47.5 +12.0/-0.2 keV. Ground-based observers were not able to find any optical counterpart. The ROTSE-III telescope was used to get limits within the first ~ 1 minute after the burst; limiting magnitudes were in the 15 to 17 range in images taken from 1 to 6 minutes after the trigger (GCN 9622). The RAPTOR telescope had similar results in data taken essentially simultaneously with that of ROTSE-III (GCN 9624)." GRB 090706 13:40:00 -47:06:00 311.45 14.97 Centaurus 2009/07/06 06:47:40.43 Fermi The GBM showed two peaks lasting a total of ~100 seconds. The spectrum was fit by a simple power law with index -2.16 +/- 0.09. GRB 090704 13:52:49.2 22:47:24 18.97 75.44 Bootes 2009/07/04 05:47:43 INTEGRAL 0 This burst was found in offline analysis of low significance IBAS triggers. It had a duration of about 60 seconds. The burst did not cause an automatic trigger because it was so far off-axis, causing it to have very low signal to noise. GRB 090703 00:03:00 09:42:00 103.6 -51.34 Pisces 2009/07/03 07:54:02.48 Fermi 0 The GBM light curve showed a single peak lasting about 9 seconds. The spectrum was fit by a simple power-law with index -1.72 +/- 0.06. GRB 090701 07:39:00 -42:06:00 255.48 -9.77 Puppis 2009/07/01 07:54:02.48 Fermi 0 A single pulse lasting 12 seconds was seen in the GBM. The spectrum was fit by a simple power law with index 1.84 +/- 0.09. GRB 090630 09:24:00 -46:36:00 270.18 2.66 Vela 2009/06/30 07:27:21.17 Fermi 0 The GBM light curve had a single peak lasting approximately 5.1 seconds. The spectrum was fit by a power-law with exponential cutoff: index = -1.5 +/- 0.1, Epeak = 79 +/- 13 keV. A Band function could also be used to fit the spectrum, with alpha -1.5 +/- 0.2, beta = -2.3 +/- 0.4 and Epeak = 71 +/- 24 keV. GRB 090628 15:48:12.65 -15:59:05.6 353.08 29.2 Libra 2009/06/28 21:20:12 Swift 0 "This burst had a single peak lasting approximately 5 seconds. Because of Earth limb constraint, no prompt slew was possible. Swift slewed after a ~2700 second delay. At that time the XRT showed an uncatalogued point source within the BAT error circle (GCN 9586). The UVOT also imaged the field beginning 2790 seconds after the trigger. No afterglow candidate was found (GCN 9587). No OC was reported from ground observers. Upper limits below ~20.5 were reported from GROND (GCN 9591) in data obtained 4.8 hours after the burst, and from Calar Alto (9589) in imaging done starting 1.43 hours after, where upper limits in R were ~22.." GRB 090626 11:17:00 -36:06:00 282.35 22.97 Centaurus 2009/06/26 04:32:08.88 Fermi 0 The GBM light curve had four main peaks and lasted approximately 70 seconds. The spectrum was fit by a Band function with alpha = -1.29 +/- 0.02, beta = -1.98 +/- 0.02 and Epeak = 175 +/- 12 keV. GRB 090625B 00:09:02.83 -65:46:49.2 309.78 -50.78 Tucana 2009/06/25 13:26:21 INTEGRAL 0 "This GRB was localized by INTEGRAL and had a duration of approximately 11 seconds. The field was observed by Swift using the XRT about an hour after the burst (at 14:30:13), and a faint x-ray source was detected. However, because of the long time delay it was not possible to determine if any source was fading in the initial observations (GGN 9573). However, subsequent analysis did show that the source had faded, suggesting that it was the afterglow of the GRB (GCN 9580). From the ground, observations were made with the Faulkes Telescope South (GCN 9574), with only upper limits available (R > 19.3, R > 1.0 coadded) in data obtained 120 seconds after the IBAS trigger. Similarly, for GROND observations, upper limits in its seven bands were all fainter than ~ 20.5 (GCN 9578)." GRB 090625A 01:21:00 -06:24:00 142.99 -68.11 Cetus 2009/06/25 05:37:00.21 Fermi 0 This GRB had multiple weak pulses. It lasted approximately 51 seconds. The spectrum was fit by a power-law with exponential cutoff. The power-law index was -0.6 +/- 0.2 and the cutoff energy was Epeak = 198 +/- 36 keV. GRB 090623 20:36:00 -43:12:00 357.66 -36.73 Microscopium 2009/06/23 02:34:17.56 Fermi 0 At least five peaks were seen in the GBM light curve, which lasted 72 seconds. The spectrum was fit by a power law with exponential cutoff. The index was -0.73 +/- 0.04 and the cutoff energy was Epeak = 476 +/- 39 keV. GRB 090623 20:36:00 -43:12:00 357.66 -36.73 Microscopium 2009/06/23 02:34:17.56 Fermi 0 At least five peaks were seen in the GBM light curve, which lasted 72 seconds. The spectrum was fit by a power law with exponential cutoff. The index was -0.73 +/- 0.04 and the cutoff energy was Epeak = 476 +/- 39 keV. GRB 090621B 20:53:52.8 69:01:41.5 104.31 15.28 Cepheus 2009/06/21 22:07:25 Swift none has been reported. "This burst had a single spike lasting less than 128 millisecond. The XRT began observing the field ~71 seconds after the trigger, finding a faint, uncatalogued x-ray source within the BAT error circle. The UVOT starting observing the field 76 seconds after the trigger, but no OC was found In the initial data. The UVOT limiting magnitude was approximately 18 (unfiltered). Observations from the ground were not able to find an afterglow. However, observers using the 4.2 meter William Herschel Telescope in the Canary Islands obtained observations from ~1.7 to ~2.3 hours after the trigger. While they found no afterglow, they did find a very faint, non-variable object within the XRT error circle in their i-band images. No magnitude is reported (GCN 9547). Observers at the Russian-Turkish 1.5 meter telescope (Turkey) confirmed the object above, saying they marginally detect it. They also report a brighter, point-like object with Rc = 21.8 +/- 0.06 (based on USNO-B1). Their limiting magnitude is reported to be Rc ~ 23.6 (GCN 9549). The VLA was used to observe the field at 8.46 GHz beginning 14.6 hours after the burst. No source was found to a 3 sigma limit of 54 uJy (GCN 9555). " GRB 090621D 00:49:00 -22:36:00 115.84 -85.44 Cetus 2009/06/21 10:43:45.14 Fermi 0 This burst had two peaks and it lasted 39.9 seconds. The spectrum was fit by a simple power-law with index -1.66 +/- 0.05. GRB 090621C 17:10:00 -28:28:00 356.06 6.76 Ophiuchus 2009/06/21 10:00:52.10 Fermi 0 The burst had multiple short peaks and a duration of ~59.9 seconds. The spectrum was fit by a power-law plus exponential cutoff. The index is -1.4 +/- 0.1 and the cutoff energy is Epeak = 148 +/- 34 keV. GRB 090621A 00:44:04.58 61:56:30.2 122.07 -0.92 Cassiopeia 2009/06/21 04:22:43 Swift none has been reported. This burst showed weak emission for ~8 seconds, but it was followed by a second trigger approximately 4 minutes later from the same location, possibly suggesting an extended prompt phase. The XRT began observing the field 117 seconds after the trigger. There was an uncatalogued, variable x-ray source within the BAT error circle. There was a bright peak that occurred ~250 seconds after the trigger, another possible indication of an extended prompt phase. The UVOT also observed the field, but in the initial 150 second finder chart exposure taken starting 122 seconds post-trigger, no OC is found. GRB 090620 15:50:00 61:12:00 94.44 44.8 Draco 2009/06/20 09:36:23.47 Fermi 0 This had a single peak lasting approximately 16.5 seconds. The spectrum was fit by a Band function with alpha = -0. 40 +/- 0.04, beta = -2.44 +/- 0.10 and Epeak = 156 +/- 6 keV. The burst was independently detected by INTEGRAL. GRB 090618A 19:35:58.69 +78:21:24.3 110.38 24.33 Draco 2009/06/18 08:28:29 Swift Afterglow seen at m ~ 14. 0.54 "This burst had a multi-peak structure and lasted about 130 seconds. The XRT began observing the field 121 seconds after the trigger and found a bright, uncatalogued x-ray source within the BAT error circle. The UVOT also observed the field, beginning 128 seconds after the trigger. It found a candidate OC at m = 14.36 in a 150 seconds unfiltered finder chart exposure. From the ground, the OC was also seen by observers at the Palomar 60 telescope, who reported an magnitude r’ = 13.8 (GCN 9513). It was also seen by observers at the KAIT telescope (Lick observatory), who reported magnitudes as follows (GCN 9517): t_mid(seconds) exp(s) mag mag_err --------------------------------------- 76 2.0 13.61 0.03 92 2.0 13.99 0.04 117 2.0 13.50 0.03 237 20.0 14.02 0.02 436 20.0 14.73 0.02 729 20.0 15.26 0.02 2601 20.0 16.22 0.02 7329 120.0 17.02 0.03 They also fit a decay law to the light curve, with alpha = -1.08 +/- 0.05 up to ~600 seconds, and alpha = -0.70 +/- 0.02 thereafter. Observers at the Shane 3m telescope, also at Lick Observatory, were able to obtain a spectrum of the OC beginning about 20 minutes after the trigger. Their spectrum covers the region from 3200 to 4400 Angstroms, and they report absorption features from Mg II, Mg I and Fe II, all at a redshift of z = 0.54. Since they see no Lyman-alpha absorption (implying z < 1.6 given their wavelength range), they take this to be the redshift of the burst. Inspection of the field of the GRB in SDSS images has shown a faint object corresponding to the position of the OC. The object is seen in the r (22.7 +/- 0.3) and I (22.2 +/- 0.4) frames, but not in u, g or z (GCN 9526). This is one of the few bursts detected in the radio. Observers using the AMI Large Array observed the field of the GRB in a band from 14.6 to 17.5 GHz. The observations were carried out from 18.25 to 21.25 hours after the trigger. The burst is clearly detected, with a flux density of 550 uJy (rms noise is 85 uJy). The observations indicate that the flux increased from 425 to 640 mJy between the first and second half of the observations, but this increase is not certain (GCN 9532). The VLA was also used to observe the field. The observations, carried out at 8.46 GHz approximately a day after the burst, showed a source coinciding with the OC discovered by the P60 (GCN 9517) at a flux density of 383 +/- 47 uJy (GCN 9533). " GRB 090616 06:52:00 -03:42:00 216.29 -1.56 Monoceros 2009/06/16 03:45:42.53 Fermi 0 This burst had a single pulse that lasted approximately 2.7 seconds. The spectrum was fit by a power law with index -1.27 +/- 0.07. GRB 090612 05:24:18 17:45:00 186.87 -10.11 Taurus 2009/06/12 14:50:50.490 Fermi 0 The GBM light curve showed a single strong pulse which was preceded by a weak pre-trigger. The total duration of the burst was ~ 58 seconds. The spectrum was fit using a Band function with alpha = -0.6 +/- 0.1, beta = -1.9 +/- 0.1 and Epeak = 357 +/- 59 keV. GRB 090610C 04:42:00 30:18:00 170.8 -10.44 Auriga 2009/06/10 21:12:07.73 Fermi 0 This burst had a single peak lasting approximately 18.1 seconds. The spectrum was fit with a simple power law of index -1.62 +/- 0.08. GRB 090610B 18:24:00 -42:06:00 352.08 -13.11 Corona Austrina 2009/06/10 17:21:31.90 Fermi 0 This burst was triggered by single short pulse which was followed by a broad pulse at T+80. The total burst duration was 202.5 seconds. The spectrum during the the ~10 seconds centered at T0 was fit by a power law with exponential cutoff. The index was -0.46 +/- 0.36 and the cutoff energy Epeak = 104.90 +/- 16.70 keV. The spectrum of the second pulse was fit by a simple power law with index -1.66 +/- 0.07. GRB 090610A 05:37:00 35:24:00 173.55 1.87 Auriga 2009/06/10 15:33:25.94 Fermi 0 This burst had a single pulse lasting 6.5 seconds. The spectrum was fit using a power law with index -1.30 +/- 0.03. GRB 090608 06:41:00 -37:25:00 246.39 -18.01 Puppis 2009/06/08 01:15:26.60 Fermi 0 The GBM showed multiple peaks lasting a total of about 61 seconds. The spectrum was fit by a power law with index = -1.83 +/- 0.07. GRB 090607A 12:44:40.57 44:06:19.5 127.08 72.97 Canes Venatici 2009/06/07 05:30:17 Swift none has been reported. "This burst had several spikes in the BAT light curve. It lasted approximately 5 seconds. Swift slewed immediately to the burst and began observing with the XRT 70 seconds after the trigger. A fading, uncatalogued x-ray source was found. A mag 6.3 star within the UVOT field prevented prompt observations with that instrument, though images in u were obtained 75 seconds after the burst, with limits of u > 21.2 (GCN 9495). In later observations, taken several hours later, no OC was found to magnitudes fainter than 20 in uvw1 and v (GCN 9495). From the ground, the Faulkes telescope north observed in the first 30 to 80 minutes after the burst in R and I’. No OC was found to fainter than 21 in each band (GCN 9492). Observations were also made with the GRAS001 0.3 meter telescope in New Mexico. The observations were done about an hour after the trigger. The unfiltered images did not show any source to fainter than m = 18.5 (GCN 9493)." GRB 090606 09:48:00 -70:30:00 288.71 -12.88 Carina 2009/06/06 11:18:08.00 Fermi 0 This was a long weak pulse in the GBM, lasting approximately 60 seconds. The spectrum was fit by a power law with index -1.63 +/- 0.09. GRB 090602 16:36:00 -65:00:00 323.94 -11.75 Triangulum Australe 2009/06/02 13:32:22.85 Fermi 0 The GBM light curve had a broad single peak with a duration of 16 seconds. The spectrum was fit using a power law with exponential cutoff: index = -0.56 +/- 0.14, Epeak = 503 +/- 91 keV. GRB 090531B 16:48:15 -36:01:28 347.22 5.76 Scorpius 2009/05/31 18:35:56 Swift GRB 090531A 11:54:44 07:47:57 265.52 66.46 Virgo 2009/05/31 01:45:17 Swift GRB 090530B 04:53:00 13:47:00 185.9 -18.57 Orion 2009/05/30 18:14:24.42 Fermi 0 This was a long, soft burst lasting 194 seconds (T90). It had a FRED shape with a double peak. The spectrum was fit by a Band function with alpha = -0.71 +/- 0.06, beta = -2.42 +/- 0.05 and Epeak = 67 +/- 3 keV. GRB 090530A 11:57:34 26:35:00 212.46 77.98 Leo 2009/05/30 03:18:18 Swift GRB 090529A 14:09:53 24:26:13 28.65 72.16 Bootes 2009/05/29 14:12:35 Swift GRB 090529C 10:51:00 47:18:00 164.28 59.01 Ursa Major 2009/05/29 13:32:00.49 Fermi 0