via io9:

video footage of a binary star system exploding into space.

“This isn’t to be confused with a supernova, which is a star that has collapsed in on itself causing it to completely self-destruct — rather, a nova is a cataclysmic nuclear explosion that happens in a binary system when one star sucks away too much hydrogen from its partner. A white dwarf can only hold so much hydrogen before it reaches critical mass and completely explodes, thereby ejecting all its excess mass into space.”