Overview Animation of Gamma-ray Burst | NASA Goddard FriendsofNASA.org: [no audio] Gamma-ray bursts (GRBs) are the most luminous explosions in the cosmos. Astronomers think most occur when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole, as illustrated in this animation. The black hole then drives jets of particles that drill all the way through the collapsing star at nearly the speed of light. These jets pierce through the star, emitti