Researchers have tracked the progress of supernova 1987A since the star began to explode.

NASA/STScI/CfA/P.Challis

Scientists have finally figured out what’s at the core of a nearby supernova. Supernova 1987A is the first stellar explosion we’ve been able to track in detail since its inception, and we now know it left behind a hot explosion. Neutron star.

After a star explodes in a supernova, there are two possible objects that can be left behind: a neutron star, which is a dense stellar body composed primarily of neutrons, and…