The black hole closest to Earth is not quite what we thought; Fahm – 03/03/2022

The closest black hole to Earth set in 2020, Nothing is as we thought. In fact, it doesn’t even exist. Astronomers corrected the discovery: it is a “vampire” system, in which one star sucks life from another star.

In 2020, a team from the European Southern Observatory (ESO) announced the closest black hole to Earth, four times the mass of the Sun, just 1,120 light-years away, in the HR 6819 system. Leuven, Belgium, opposed this discovery.

The two groups got together and conducted a new study that clarifies the information. posted yesterday (2), In the Journal of Astronomy and Astrophysicsunder the title “HR 6819 is a binary system without a black hole”.

The article reveals that, in fact, there is not a black hole at the site, but a system of two stars, in a rare and short-lived stage of their evolution, as one absorbs the other. An opportunity for astronomers to explore how these “vampire” stars behave.

naked star

The first team’s hypothesis that it was a black hole was based on assumptions that have not been properly verified. At the time, the telescope’s data was best explained by the fact that HR 6819 was a triple system, with two large stars orbiting a black hole – one very close, at 40 days’ orbit, and the other very far away.

However, the Belgians interpreted the same data in another way: only two stars, very close to each other, can be in an orbit of 40 days, with no black hole between them.

And this scenario will work only if one of the stars is “naked”, that is, it has lost a significant part of its mass. A very light star will complete the calculations, without the need for a third, invisible element in the system.

Since they were already at the limit of current data, the two teams worked together to get newer and clearer information, using the latest VLT (Very Large Telescope) telescope in southern Chile and its VLTI interferometer.

“We agreed that there were two light sources in the system. The question then is whether they orbit each other, describing close orbits, as in the “naked” star scenario, or if, on the contrary, they are far from each other, as in the scenario black hole,” Thomas Rivinius, an astronomer at ESO in Chile and lead author of the first paper, explained in a statement.

To distinguish between the two hypotheses, the researchers used instruments called Gravity, mounted on the VLTI telescope, and the Muse (Multi Unit Spectroscopic Explorer), on the VLT.

“Moses confirmed that there is no bright companion in outer orbit, while the spatial resolution of gravity was able to distinguish the two light sources, separated by only one-third of the distance between the Earth and the sun,” said astrophysicist Abigail. Led data comparison.