Black Holes

Black holes are common. But actually counting them is no easy task. Even the brightest can be hard to see. Of course, "bright black holes" is a bit of an oxymoron. But when supermassive black holes at the center of a galaxy feed, the material falling into them heats up, giving off a bright glow across the electromagnetic spectrum . Infrared light, in particular, is good to look for when black-hole hunting . Some feasting black holes are obscured by gas and dust , which absorbs much of their glow but they still shine in the infrared. It's no surprise, then, that NASA's infrared WISE spacecraft found a bunch.