Gamma_ray burst from supernova. Animation clip 3 of 11 showing a gamma_ray burst GRB being produced during a supernova, the death of a massive star. GRBs are extremely energetic releases of gamma rays, visible across the universe in the direction the radiation is emitted. The GRB is the bright glow seen at the start of the clip. This is followed by the collapse of the core and the ejection of the star磗 outer layers yellow. The remnant will be a neutron star or black hole. The precise cause of a GRB varies depending on the length. Longer ones as here are thought to occur during the death and collapse of massive rapidly rotating stars. Shorter ones are thought to occur during the merger of colliding neutron stars as they form a black hole. Later clips in this sequence K003/2670_2660 show the process of neutron star merger in detail, as modelled by the Damiana supercomputer at Germany磗 Max Planck Institute for Gravitational Physics.