Quasar

Short for Quasi-stellar Radio Source. A quasar behaves like a small galaxy powered by a super massive black hole, most of the time. Every so often a quasar devours some form of mass (its black hole does the actual devouring) and becomes extremely bright. The brightest known quasar is more than one hundred times as bright as our entire galaxy even though it is only several light weeks (a light week is the distance light travels in a week) across, as opposed to our milkyway galaxy, which is 100,000 light YEARS across. It is theorized that, for the brightest quasar to burn as brightly as it does, it must devour as many as 10 stars a year. Also, there are no quasars nearby, because quasars haven't existed for billions of years. It's just that only now are we seeing the ones that were far enough away from us, so that their light could be travelling through space for billions of years.