Mysterious Explosion Caused Massive Star to Brighten

Stars have onion-like layers that blow off in fiery explosions before a final killing blow—a supernova—turns them into black holes, according to a new theory of star death. These repetitive blasts are too powerful to be caused by stellar winds, as previously believed—so they must come from a new type of explosion originating in the star's interior, astronomers say. National Geographic Article...