These cosmic gluttons may be tight

Astronomers report a candidate pair of supermassive black holes only one-third of a light-year apart

Two astronomers may be seeing double. They report evidence that a galaxy about 4 billion light-years from Earth houses not one, but two giant black holes. Moreover, the duo might be separated by only one-third of a light-year — less than 10 percent of the distance between the sun and its nearest star system, Alpha Centauri.