Discovered the black hole closest to Earth
Astronomers found a black hole 1,000 light-years from Earth to form a system with two stars.
Simulate the HR 6819 system containing the black hole closest to Earth. Photo: ESO.
The new black hole is in the southern constellation Telescopium, along with two companion stars bright enough to see with the naked eye. But you won't see the black hole itself, because it has gravity so strong that nothing can escape, including light.
The team, led by astronomer Thomas Rivinius at the Southern European Observatory, discovered a black hole while studying a system they thought was a binary star system. They used a 2.2-meter MPG / ESO telescope at the La Shilla Observatory in Chile to observe the HR 6819 in a broader study of binary star systems. When analyzing the data, the team suddenly realized that the third object hidden in the system was a black hole.
Without observing the black hole directly, astronomers can infer its existence based on the gravitational interaction with the other two objects in the system. After observing the HR 6819 system for several months, they mapped the orbits of the stars and deduced that a large object was definitely hiding in the system.
Observational results also show that one of the two stars orbits the invisible object in orbit for 40 days while the other star lies at a much larger distance. They calculated the object to be a black hole with a stellar mass, formed by the collapse of a dead star four times larger than the Sun. Rivinius and colleagues conclude that the HR 6819 system contains the black hole closest to Earth that researchers have known.
The second closest black hole after HR 6819 is located 3,000 light-years from Earth in the constellation Monoceros. Astronomers estimate there are millions of black holes in the Milky Way alone. The black hole in the HR 6819 system is one of the first stellar black holes in our galaxy that does not release X-rays when interacting with companion stars.