A little less than a billion years ago, a star passed a little too close to a black hole. Under tremendous gravitational stress, it puffed and swelled as it heats before its gas was stripped off into the black hole’s accretion disk, sending a tide of gas boiling through the mass swirling down into the event horizon. As it fed the black hole, a short-lived new point of light at the center of a galaxy — light which just arrived to Earth-based telescopes.
