Gamma ray burst eruption. Image 5 of 5. Computer artwork of the jet (white) of a gamma ray burst, erupting from a star's surface (across bottom). This is based upon the collapsar theory of GRBs that says GRBs result from the collapse of the core of a massive star. A black hole forms when the core collapses. The spin or magnetic field of the black hole forms jets from material that is being ejected at near the speed of light. The jets are the source of the gamma rays of the GRB, a massive short-lived burst of energy that is 100s of times brighter than an ordinary supernova. For GRB formation, see images R670/148-152. For GRB jets, see images R670/153-154.