Gamma ray bursts are the most powerful explosions in the Universe, emitting more energy in an instant than our Sun can give off in its entire lifetime. But they don’t just blast out radiation, they also eject matter. And it turns out, they eject matter very very quickly – at 99.9997% the speed of light.
This discovery was made by a large group of European researchers. They targeted the European Southern Observatory’s robotic La Silla Observatory at two recent gamma ray burst explosions. The observatory receives its targets automatically from NASA’s Swift satellite, and it autonomously zeros in to capture as much data as possible during the first few seconds after the explosion is detected.
In two cases, La Silla observed the light curve of the explosion, and measured the peak. And measuring the peak is the key, since it allowed them to calculate the velocity of matter ejected from the explosion. In the case of these two explosions, the matter was calculated to be traveling 99.9997% the speed of light.
Original Source: ESO News Release