NASA's Hubble Space Telescope has provided the strongest evidence yet that short-duration gamma-ray bursts are triggered by the merger of two small, super-dense stellar objects, such as a pair of neutron stars or a neutron star and a black hole.
The definitive evidence came from Hubble observations in near-infrared light of the fading fireball produced in the aftermath of a short gamma-ray burst (GRB). The afterglow reveals for the first time a new kind of stellar blast called a kilonova, an explosion predicted to accompany a short-duration GRB.