Astronomers say they have discovered a new black hole about 1,000 light-years from Earth,media outlet The Verge reported. If their findings are confirmed, this small black hole will be the closest black hole ever discovered to our planet. As a black hole, the object is impossible to see directly from instruments on Earth, because no light can escape from it. So, according to a new study published in the journal Astronomy and Astrophysics, scientists at the European Southern Observatory (ESO) in Chile actually infer that the object is where they think it is based on the motion of nearby stars.
The team tried to figure out the strange behavior of two stars approaching each other in space, in a system called HR 6819. They are all in the same galaxy, similar in mass and size, but their behavior is very different. “One of them is spinning very fast, so fast that it’s almost flying away. Thomas Rivinius, an ESO scientist who led the study, told The Verge that the other one had little rotation. At the same time, they all move in space at different speeds.
Astronomers have been curious about the binary system for years, and some believe there must be a third object nearby, causing the two stars to move like them. Now, after years of speculation, Rivinius and his team have decided to re-observe it using the La Silla Observatory at ESO in Chile. They tracked the movements of these stars and measured their condition in space. They found that the stars appeared to be orbiting something else, an object four times the mass of the sun. But at first glance, there seems to be nothing at the center of the system. This means they either rotate around a hard-to-see star or are black holes.
To narrow the range of options, Rivinius and his team came up with the faintest of stars, possibly the stars of this mass, but ultimately found no trace of such dark objects. “We can rule out any type of star having this mass, ” Rivinius said. “So if there’s something in the system that has that quality, it’s a black hole. “
Compared with some other black holes in the universe, black holes in this system are very small. For example, the supermassive black hole at the center of the Milky Way is thought to be 4.6 million times the mass of the sun, about 26,000 light-years from Earth.
“We only know dozens of such black holes, but we suspect there may be a billion of them in the Milky Way, ” says Rivinius. “The fact that it’s so close actually means it can be very rare. “