While 1,000 light-years may seem like a vast distance away from Earth, it’s practically in our backyard because of the scale of the universe. And it’s just 1,000 light-years away from Earth where astronomers found the closest black hole to the Earth in the double-star system HR 6819.
The stellar black hole was discovered by the way it interacts with two stars nearby. It’s unique in that it can be potentially seen with the naked eye — if you live in the southern hemisphere, that is.
"Given how fast the star was moving around this unseen companion, they calculated the mass was so high it had to be a black hole," explains Lake Effect astronomy contributor Jean Creighton.
She notes that the previous black hole thought to be closest to Earth was three times farther away, making the HR 6819 discovery significant in helping us understand how black holes are made. And the more data collected, the better statistics are to analyze what is the distribution of black holes and how they might form.
"Every time you find a black hole is a victory, and the fact that it’s close enough that you can see the accompanying star together is definitely unique," says Creighton. "In most cases, you haven’t any chance of doing that."