NGC 6240 is a puzzle to astronomers. For a long time, astronomers thought the galaxy is a result of a merger between two galaxies, and that merger is evident in the galaxy’s form: It has an unsettled appearance, with two nuclei and extensions and loops. NGC 6240 is about 400 million light years away, in … Continue reading Astronomers Find a Galaxy Containing Three Supermassive Black Holes at the Center