Over the past few decades, a consensus has slowly emerged as astronomers have armed themselves with better data and computer models. As described in the August 2006 issue of Sky & Telescope (page 30), GRBs that last a few seconds or longer result from the cataclysmic explosions of massive stars. In some of these explosions, some of the energy is channeled into twin jets of electromagnetic radiation and particles that punch through the star. The matter in these jets travels at very close to the speed of light. Outside the star, faster blobs of matter catch up to slower blobs. Calculations indicate that these high-speed collisions can generate the eruptions we see as GRBs.
The movies on this page show some of the processes ultimately responsible for one of Mother Nature's most violent creations.