Cygnus X-1: Still A 'Star' After All Those Years
Monday, August 31, 2009 - 13:35
in Astronomy & Space
Since its discovery 45 years ago, Cygnus X-1 has been one of the most intensively studied cosmic X-ray sources. About a decade after its discovery, Cygnus X-1 secured a place in the history of astronomy when a combination of X-ray and optical observations led to the conclusion that it was a black hole, the first such identification.