Astronomers have identified the largest black hole ever discovered in the Milky Way, with a mass 33 times that of the Sun, according to a scientific paper published on Tuesday.
The black hole, called Gaia BH3, was discovered "accidentally" while analyzing data collected by the European Space Agency's Gaia mission, Pasquale Panuzzo, one of the astronomers at the Paris Observatory National Center for Scientific Research (CNRS), told AFP.
Gaia, which aims to map the Milky Way galaxy, discovered the black hole BH3 in the constellation Eagle, 2 light-years from Earth.
Because the telescope used by the Gaia mission can pinpoint the location of stars in the sky, astronomers were able to determine their orbits and measure the mass of an invisible companion star, which turned out to be 33 times the mass of the Sun.
Further observations with telescopes on the ground confirmed that this is a black hole, the mass of which is much higher than those discovered so far in the Milky Way.
"No one expected to find a very nearby and hitherto undetected massive black hole. Such a discovery can be made once in a researcher's professional career," P. Panuzzo said in a press release.
The stellar-mass black hole was discovered after scientists noticed "wobbly" motions in the star orbiting it.
"We saw a slightly smaller (about 25 percent) and brighter star than the Sun orbiting an invisible companion," Panuzzo said.
Stellar-mass black holes form when giant stars collapse at the end of their lives and are smaller than supermassive black holes, whose origins are still unknown.
Such giants have already been detected in distant galaxies with the help of gravitational banks.
But "never in our house," said P. Panuzzo.
BH3 is a "sleeping" black hole, too far away from its companion star to suck up matter, so it emits no X-rays and is therefore difficult to detect.
The mission's Gaia telescope also detected the first two inactive black holes in the Milky Way, Gaia BH1 and Gaia BH2.
The mission "Gaja" has been carried out for the past ten years at a cost of 1,5 million. kilometers from the earth, and in 2022 provided a three-dimensional more than 1,8 billion a map of the stars and their trajectories.
Jūras Barauskas (AFP)
