Black holes should be common in our Milky Way galaxy, but their dark nature means only dozens have been discovered to date (Dec 12, 2019) . Here are a few nearby black holes astronomers know a little about.
Cygnus X-1
The third-closest known black hole to Earth is in the Cygnus X-1 system. The black hole reveals itself to astronomers as it steals material from blue supergiant star HDE 226868. (Credit: Roen Kelly/Astronomy after NASA)
Scientists suspect the black hole Cygnus X-1 began life as a star 40 times the mass of the sun. It likely collapsed directly to form a black hole some 5 million years ago — around the same time the first mammoths show up in fossil records on Earth.
6,000 light-years away
14.8 solar masses
The black hole has an event horizon 185 miles across — about the length of New Hampshire.
Cygnus X-1’s companion star is a blue supergiant variable star that orbits every 5.6 days at just one-fifth of the sun-Earth distance.
Tour 10 of the Closest Black Holes to Earth
Cygnus X-1
The third-closest known black hole to Earth is in the Cygnus X-1 system. The black hole reveals itself to astronomers as it steals material from blue supergiant star HDE 226868. (Credit: Roen Kelly/Astronomy after NASA)
Scientists suspect the black hole Cygnus X-1 began life as a star 40 times the mass of the sun. It likely collapsed directly to form a black hole some 5 million years ago — around the same time the first mammoths show up in fossil records on Earth.
6,000 light-years away
14.8 solar masses
The black hole has an event horizon 185 miles across — about the length of New Hampshire.
Cygnus X-1’s companion star is a blue supergiant variable star that orbits every 5.6 days at just one-fifth of the sun-Earth distance.
Tour 10 of the Closest Black Holes to Earth