Gamma-Ray Bursts (GRBs) are sudden flashes of high energy radiation in the gamma-ray region of the electromagnetic spectrum (20 keV and above). They occur at random times and in random locations across the celestial sphere. Unitl 1997, the identification of counterpart objects at other wavelengths had never been found, primarily due to the GRB location uncertainties and the inability for rapid, accurate follow-up observations with ground based telescopes.

Observations of Gamma-Ray Bursts

GRBs are observed to vary in intensity on a variety of time scales ranging from sub-milliseconds to hundreds of seconds, while their durations span over five orders of magnitude. A sample variety of GRBs observed by BATSE on the CGRO are shown at right. The log-normal distribution of burst durations, characterized by the T90 parameter, shows a clear bimodality, suggesting a "short" and "long" class of GRBs. It has further been established that events falling in the "short" class generally tend have a harder spectrum, i.e. they emit more energetic photons.

Graduate students research GRBs

For the latest news on Gamma-Ray Bursts, a review of GRBs, and recent GRB news headlines, check out the Space Science Laboratory Home Page at NASA's Marshall Space Flight Center

Gamma-Ray Bursts

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