A Gamma-Ray Burst is a short flash of Gamma Rays, lasting from a few milliseconds to several minutes. Often followed by an afterglow of longer-Wavelength radiation. They were first detected in 1967 by satellites intended to detect nuclear weapons tests.
Presumed sources include supernovae and/or merger of Neutron Stars. The latter is theorized as the cause of Short Gamma Ray Bursts (SGRB), i.e., those lasting less than two seconds. Superluminous Supernovae are theorized to create Long Gamma Ray Bursts (LGRB), i.e., more than two seconds.
Compton Gamma Ray Observatory (CGRO)
Habitable Zone (HZ)
Hercules-Corona Borealis Great Wall (Her-CrB GW)
Superluminous Supernova (SLSN)