More than 30 years ago, Stephen Hawking famously placed -- and eventually lost -- a bet against the existence of a black hole in Cygnus X-1.
He was eventually proved wrong, and astronomers say the new data has now given them remarkably precise values of the black hole's mass, spin and distance from Earth.
"This new information gives us strong clues about how the black hole was born, what it weighed and how fast it was spinning," study author Mark Reid of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., said in a release Thursday. "This is exciting because not much is known about the birth of black holes."
Cygnus X-1 is a so-called stellar-mass black hole that comes from the collapse of a massive star. The black hole is in close orbit with a massive, blue companion star.
"It is amazing to me that we have a complete description of this asteroid-sized object that is thousands of light years away," Harvard-Smithsonian researcher Lijun Gou said. "This means astronomers have a more complete understanding of this black hole than any other in our Galaxy."