The white dwarf star in the galaxy M82 has gone nova (or, at least, its 11.5 million-year-old light is just reaching us now). M82 is a starburst galaxy, which means it is relatively young and generating large number of new stars. But white dwarfs are the remains of old star, and there shouldn't be more than a handful of these in M82.
What's more, when a white dwarf begins feeding off a nearby neighbor, it can collect enough material on its surface to go supernova -- and that's just what has happened.
So don't look a gift nova in the face: Just enjoy this great astronomical event!