Astronomers Spy a Giant Runaway Black Hole’s Starry Wake

Some 40 million years ago, a supermassive black hole escaped the clutches of its host galaxy, leaving a sparkling trail of young stars as it sped away into space. The rogue black hole was first picked up by the Hubble Space Telescope as a faint linear trail. Further observations made with the W. M. Keck Observatory in Hawaii revealed that the streak was a stream of blue stars stretching across a staggering 200,000 light years. The object weighs 20 million Suns and is travelling at more than 1,500 kilometres a second.