Gamma ray burst, computer artwork. This is a face- on view of a gamma ray burst (GRB) jet (white). A Wolf-Rayet star has exploded, and this jet has erupted out of the core, through the surrounding nebula (blue). This is the collapsar theory of GRBs, which says GRBs result from the collapse of the core of a massive star. The spin or magnetic field of the black hole forms two jets from surrounding material that is being ejected at near the speed of light. The jets are the source of the gamma rays of a GRB, a massive short-lived energy burst, hundreds of times brighter than an ordinary supernova. For GRB formation, see images R670/148- 152. For a GRB jet side on, see image R670/153.