Cygnus X-1: Blue supergiant pairs with black hole
Thursday, June 23, 2011 - 06:00
in Astronomy & Space
Discovered in 1964 during a rocket flight, Cygnus X-1 holds the record for being the strongest X-ray source seen from Earth. The blue supergiant star designated as HDE 226868 is just part of this high-mass X-ray binary system... the other is a black hole.
