Astrophysicists have found the first ever evidence of gigantic remains being formed from repeated explosions on the surface of a dead star in the Andromeda Galaxy, 2.5 million light years from Earth. The remains or 'super-remnant' measures almost 400 light years across. The super-remnant — larger than almost all known remnants of supernova explosions — is consistent with being built up by frequent nova eruptions over millions of years.