Gamma-ray bursts (GRBs) are the most powerful explosions in the Universe. Most GRBs are thought to be triggered by the collision of very massive and compact objects such as neutron stars or black holes, or by the explosion of incredible powerful supernovae – or hypernovae.
No one can predict where the next gamma-ray burst will come from, but one or two will erupt every day in the sky. They typically last only a few tens of seconds.
ESA’s Integral gamma-ray observatory detects an average of about 10 GRBs a year. The spacecraft has also confirmed the existence of a new population of faint gamma-ray bursts, located in our cosmic neighbourhood. They are possibly generated the collapse of a massive star that does not present the characteristics of a supernova or hypernova, or by the merger of two white dwarfs (small and dense stars about the size of Earth), or by the merger of a white dwarf with a neutron star or a black hole.