A Star Detonated as a Supernova… Twice

The beautiful supernova remnant looks a little different from other examples of stars that detonated in the past. And it should, because according to astronomers, the star that met its end exploded twice. It was a white dwarf in its former life, pulling material from a binary companion, creating the perfect conditions for a Type 1a supernova. It accumulated a blanket of helium, which exploded first, triggering a second detonation at the core of the star.