Munich: Astronomers have observed a series of gamma-ray bursts in a single day, a phenomenon unprecedented in the history of science. According to Qatar News Agency, Antonio Martin-Carrillo, an astronomer at University College Dublin in Ireland, stated in a release from the European Southern Observatory that gamma-ray bursts are almost never repeated because the event that produces them is destructive. He noted that the signal detected by scientific circles this summer "is different from any observed in the past 50 years." The nature of the event that generated the signal remains unknown. One possible scenario is the unusual collapse of a very massive star. Alternatively, an unusual star might have been destroyed by an even more exotic black hole. Gamma-ray bursts (GRBs) are flashes of high-energy radiation that occur during extremely violent events, such as the death of massive stars in powerful explosions or their destruction by black holes. They typically last from a few milliseconds to a few minutes, a time period during which they can release energy equivalent to several billion suns.