Cygnus X-1 was the First Black Hole Ever Found. New Measurements Show it's Much More Massive Than Previously Believed

New parallax measurements of Cygnus X-1 by the VLBA find it is more distant than we thought, and therefore more massive. The post Cygnus X-1 was the First Black Hole Ever Found. New Measurements Show it's Much More Massive Than Previously Believed appeared first on Universe Today.