Last week, we released the Chandra image of an object known as Cygnus X-1. At first glance, Cygnus X-1 might not look that important – even with Chandra’s excellent X-ray vision – but this is one case where it’s good not to judge a book by its cover.
First discovered in 1964, Cygnus X-1 has become one of the most heavily observed objects in the high-energy sky. And, for good reason – it’s the first object to be identified as a black hole. Think about it this way, this object was discovered just seven years after Sputnik was launched and a good five years before astronauts would walk on the Moon.
After another decade, astronomers finally began to get a handle on the true nature of Cygnus X-1. We now know that Cygnus X-1 is a system of two objects: a small black hole (about 10 times the mass of the Sun) and a blue supergiant star (about 20 times the Sun’s mass.) Even after 45 years and a slew of observations by telescopes over that time, it’s still a fascinating object that astronomers continue to study.
More: http://chandra.harvard.edu/photo/2009/cygx1/
-Megan Watzke, CXC