Nasa’s Hubble Space Telescope has detected a new kind of stellar blast called a kilonova, which happens when a pair of compact objects – such as neutron stars – crash together. Hubble observed the fading fireball from a kilonova last month, following a short gamma ray burst (GRB) in a galaxy almost 4 billion light-years from Earth.
“This observation finally solves the mystery of short gamma ray bursts,” says Nial Tanvir of the University of Leicester in the United Kingdom, who led a team of researchers conducting this research.
Many astronomers have provided evidence that long-duration gamma ray bursts are produced by the collapse of extremely massive stars; however, the cause of short gamma ray bursts has been a mystery – until now.
“We only had weak circumstantial evidence that short bursts [might be] produced by the merger of compact objects,” says Tanvir. “This result now appears to provide definitive proof.”
Kilonovas are about 1 000 times brighter than a regular nova, which is caused by the eruption of a white dwarf.
The team’s results appeared on 3 August in a special online publication of the journal Nature.