When the universe was young, some black holes were terribly greedy. One of these black holes gobbled the mass of 12 billion suns by the time the universe was only about 860 million years old. This monster is the most massive known black hole in the early universe, clocking in at roughly six times as massive as other black holes from its time, researchers report in the Feb. 26 Nature.
To estimate the mass, Xue-Bing Wu, an astrophysicist at Peking University in Beijing, and colleagues measured the speed at which gas swirls around the black hole. Today, each black hole this massive lives in the center of a galaxy containing several trillion stars. Since such galactic giants formed only relatively recently, the discovery suggests that some supermassive black holes grew much faster than the galaxies they inhabit.