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 help shed light on how the universe has changed over time.
Swing your partner
The star responsible for this expansive remnant, which stretches over 400 light-years across, is actually from one of the most diminutive types of star: a white dwarf. These stellar corpses are left behind after a smallish star dies and blows off its outer layers, leaving behind only its dense core. But in the case of this remnant, catchily named M31N 2008-12a, the culprit is not your ordinar...