CYGNUS X-1: The most massive black hole near to Earth
Astronomers observed the Cygnus X-1 system from different angles using the orbit of the Earth around the Sun to measure the perceived movement of the system against the background stars. This allowed them to refine the distance to the system and therefore the mass of the black hole. (Pete Wheeler/International Centre for Radio Astronomy Research)
An artist’s impression of the Cygnus X-1 system. A stellar-mass black hole orbits with a companion star located 7,200 light years from Earth. (Pete Wheeler/International Centre for Radio Astronomy Research)
A Hilo-based astronomer has joined a team that’s rewriting everything we know about the massive black hole Cygnus X-1.