Astronomers have discovered a star in the Andromeda galaxy that has been regularly erupting for the past million years, leaving behind one of the biggest shells of ejected material scientists have ever seen.

The new research, which was published last month in the journal Nature, not only marks the first discovery of such a super-remnant in another galaxy, it also paves the way for detecting a potentially massive population of repeatedly exploding stars, called recurrent novae, which may h