Star's bizarre behaviour reveals 'lonely' black hole

Astronomers were initially baffled when they spotted a star 16,300 light-years from our sun being flung back and forwards at speeds of several hundred miles per hour.They later found this extraordinary movement was in fact caused by a 'lonely' black hole, four times the mass of the sun, hiding in a globular star cluster. This remarkable discovery is the first time scientists have spotted a stellar-mass black hole in a star cluster by detecting its gravitational pull on another object. Scroll ...