Astronomy 101: when a star dies, it either becomes a black hole or it becomes a neutron star. Then there are these things called pulsars, which are “ultra-dense neutron stars that rotate [at] regular intervals, emitting light periodically like a lighthouse.” These pulsars can gobble up their neighbors. In other words, they’re zombies, or vampires, if you prefer. They die, then come back to life to prey on those closest to them.
One pulsar, called SAX J1808.4-3658 (you’d think they could come up with a better name for it than that) is part of a “binary system” with another star. Ol’ SAX J1808.4-3658 spins on its axis to the tune of some 401 rotations per second. SAX J1808.4-3658 circles its neighbor every two hours, and is eating it the entire time. (That’s the way I eat a Reece’s Peanut Butter Cup. I nibble at the edges, turning it, making it last.) This case of stellar undead predation is happening, or has already happened, 11,000 light-years from us, but telescopes allowed astronomers to watch the whole horrific scene. Nothing they could do for the poor victim, though. They were powerless to do anything except document it. That SAX J1808.4-3658 is bad news, alright.