File:BATSE 2704.jpg

BATSE All-Sky Plot of Gamma-Ray Burst Locations. Original caption:

The above figure illustrates the locations of 2512 gamma-ray bursts detected by the BATSE instrument after more than eight years of observation. Statistical tests confirm that the bursts are isotropically distributed on the sky - no significant quadrupole moment or dipole moment is found. At the same time, a deficiency has been detected in the number of faint bursts, interpreted as an indication that the spatial extent of the burst distribution is limited and that BATSE sees the limit or edge of the distribution. The nature of the sources remains unknown. However, their isotropic distribution on the sky along with the deficiency of faint bursts can be naturally explained if the bursts are located at cosmological distances (far beyond the Milky Way). This interpretation has been confirmed in recent years via distance estimates for optical counterparts to gamma-ray bursts.