GRB 130427A: Brightest Ever Gamma-Ray Burst Detected
An unusual stellar explosion observed on April 27, 2013 by NASA’s Swift satellite is the brightest gamma-ray burst (GRB) ever recorded, says a multinational team of astronomers.
Optical afterglow of GRB 130427A. Image credit: J. Mats / H. Lars / H. Patrik.
The event, labeled GRB 130427A, produced a jet of matter moving close to the speed of light, which was formed when a massive star collapsed to make a black hole at its center. As a result, a blast wave caused the rest of the star to expand outwards, producing a glowing shell of debris observed as an extremely bright supernova.
GRB 130427A happened in a galaxy a quarter of the way across the Universe. Although far away, this is much closer than a typical GRB allowing astronomers to confirm for the first time that the same object can simultaneously create both a powerful GRB and a supernovae.
“We normally detect GRBs at great distance, meaning they usually appear quite faint. In this case the burst happened only a quarter of the way across the Universe meaning it was very bright. On this occasion, a powerful supernova was also produced, something we have not recorded before alongside a powerful GRB and we will now be seeking to understand this occurrence,” said Prof Paul O’Brien from the University of Leicester, a co-author of the study published in the journal Science.
The jet from a gamma-ray burst emerging at nearly light speed. Image credit: NASA / Swift / Cruz deWilde.
GRBs are relatively rare phenomena, but the study of their behavior under extreme conditions enables researchers to continue testing the laws of physics.
“The rapid reaction of Swift has enabled us to discover many new and unexpected aspects of GRBs, the strong confirmation of the basic theory by this new very bright burst reassures us that we are on the right track in understanding these extraordinary explosions,” explained study co-author Prof Julian Osborne, also from the University of Leicester.
“Seeing such a bright flash a quarter of the way across the observable Universe really brings home the astonishing power of these explosions,” added study co-author Prof Nial Tanvir, also from the University of Leicester.