For this reason black holes are invisible to the eye, as lightless as the empty, dark space surrounding them. Scientists know ...

What Was the First Black Hole Ever Discovered? The first accepted black hole was Cygnus X-1. Discovered during a 1971 rocket flight, Cygnus X-1 is one of the strongest X-ray sources detectable ...

astronomers Paul Murdin and Louise Webster surmised that a known galactic X-ray source called Cygnus X-1 was, in fact, a black hole. Though we haven’t known about these awe-inspiring objects for ...