About

Welcome to the Gamma-ray Burst Real-time Sky Map. This web application is designed to give up to the minute updates on gamma-ray burst events reported by the various gamma-ray burst detecting satellites.

Afterglow – The lower energy, non-gamma-ray, light emitted during and after a gamma ray event is called the afterglow.
BAT – Burst Alert Telescope, onboard Swift.
Constellation – Each constellation is used by astronomers to designate a region in the sky.
Celestial Coordinate System (same as Equatorial Coordinate System) - Also called the celestial coordinate system. By extending the Earth's equator and geographic poles out to the celestial sphere a mapping system for celestial objects is created. It uses two coordinates; declination (latitude equivalent) and right ascension (longitude equivalent). Declination – Comparable with latitude, declination is one of two coordinates in the equatorial (or Celestial) coordinate system. Zero degrees declination is directly above Earth's equator on the sky. +90 degrees is directly above the north pole, and -90 degrees is directly above the south pole.
Electron Volt (eV) – A unit of energy. 1 eV = 1.602 x 10^-19 joules.
Epeak – The energy peak of a GRB spectrum.
Equatorial Coordinate System – Also called the celestial coordinate system. By extending the Earth's equator and geographic poles out to the celestial sphere a mapping system for celestial objects is created. It uses two coordinates; declination (latitude equivalent) and right ascension (longitude equivalent).

Galactic Coordinates – A system for mapping space that uses longitude and latitude coordinates much like global maps. The Galactic plane is the "equator" of this coordinate system, and the Galactic center (in Sagittarius) is zero degrees longitude. The north and south galactic poles are 90 degrees north and south of the galactic plane, in the northern and southern hemispheres, respectively. Since the Galaxy is not aligned with Earth's equator, the Galactic north and south poles are different from the celestial north and south poles.
Gamma-Ray – The most energetic form of electromagnetic radiation.
Gamma-Ray Burst (GRB) – GRBs are some of most powerful radiation-emitting events known in the Universe.
Gamma-ray Burst Monitor (GBM) — The instrument on Fermi that is specifically designed to detect gamma-ray bursts.
GeV – Gigaelectron Volt, 1 billion electron volts.
GRB ID - The specific identification given to all detected Gamma-ray bursts, starting with year, then month and day. A letter suffix is used if more than one burst is detected in a given day, with "A" being the first reported, "B" being the second, and so on. So GRB 090813C would be the third GRB reported on August 13, 2009.
keV – Kiloelectron Volt, 1 thousand electron volts.
LAT – Large Area Telescope, onboard Fermi.
Latitude – The angular measurement (in degrees) above or below the galactic plane in the Galactic Coordinate system.
Longitude – The "East West" measurement (in degrees) in the Galactic Coordinate system, with Longitude 0^o being defined as the line from the sun through the galactic center.
MeV – Megaelectron Volt, 1 million electron volts.
Pseudo-redshift - A redshift determined by some means other than spectral line shifts. These could be obtained through photometric measurements or x-ray absorption measurements.
Redshift – The shift of spectral lines caused by the expansion of the universe - this is the cosmological redshift, and is distinct from the Doppler shift. Determining the degree by which light has been redshifted is used to measure the distance of the emitting object via Hubble's law. Redshift is often abbreviated with "z".
Right Ascension – Comparable to longitude, right ascension is one of two coordinates in the equatorial coordinate system. Right ascension is measured in time units, not degrees.
Star Field – An image showing the location of the GRB and nearby known fixed stars.
T90 - The period over which 90% of the total background subtracted counts from a GRB are observed. The time interval begins at the point where 5% of the total counts have been observed. This is an oft-quoted measure of gamma-ray burst duration.
UTC – Coordinated Universal Time, where leap seconds are factored into Greenwich Mean Time.
UVOT – Ultraviolet and Optical Telescope on board Swift.
XRT – X-ray Telescope, onboard Swift.
z (same as Redshift) – The decrease of lights energy due to being emitted by an object moving away from the observer, the observer moving away from the emitter, or both. Determining the degree by which light has been redshift is used to measure the distance of the emitting object. Redshift is often abbreviated with "z".

GRB Raw Data

We are now making our GRB data available to the public as an XML file, which will allow custom applications (like the GRB Skymap on this page) to be built by anyone who wants. You can find the raw XML data file at http://grb.sonoma.edu/grbs.xml