First long gamma-ray burst ever observed at centre of ancient galaxy

For the first time, an international team of astronomers has observed a long gamma-ray burst near the centre of an ancient galaxy. This is special because these kinds of gamma-ray bursts typically occur when massive stars collapse or when neutron stars circle each other for a long time, and there are no such stars at the centre of ancient galaxies. The team, led by Andrew Levan (Radboud University), are publishing their findings in Nature Astronomy. The general consensus used to be that long gamma ray bursts of at least a few seconds can only occur when a very heavy star collapses into a supernova at the end of its life. In 2022, a second potential trigger of long gamma ray bursts was uncovered when two large stars, which had been orbiting each other all their lives, turned into neutron stars at the end and collided into a kilonova. Now in 2023, it seems that long gamma ray bursts can occur in a third way. "Our data indicate that this is a case of two separate neutron stars merging.