Russian scientists have specified the mass of a black hole in 9 thousand light years

Russian scientists have calculated the mass of the black hole MAXI J1348-630. This was reported by the press service of Moscow State University, and a scientific article was published in Q1 Astronomy and Astrophysics.
In 2019, astronomers discovered a new source of bright X-rays in the constellation Centaurus. The brightness gradually increased, and in a few days a new X-ray source eclipsed the Crab Nebula. Subsequently, it turned out that the object, called MAXI J1348-630, is a black hole, or a neutron star. However, since the distance to it was unknown, it was impossible to determine the exact mass of the object and reliably classify it. The mass of neutron stars is less than 3 solar masses, and the mass of “stellar” black holes is from 3 to 50 solar masses.
However, the Russian-German telescope SRG recently discovered a giant dust ring around the object, formed as a result of a short-term flash. The radiation of the object was reflected from this ring at different points, and therefore came to the Earth with a delay – the effect of a “light echo” appeared. From this echo, Russian scientists were able to calculate the distance to MAXI J1348-630 – it is approximately equal to 9 thousand light years. This made it possible to more accurately determine the mass and finally make sure that the X-rays come from a black hole.
“The obtained value is consistent with other methods, while it has a smaller spread. As a result, the mass turned out to be 2 times more than the initial estimates. It is important to carry out such measurements in order to test the correctness of our knowledge and theories about the Universe and its development. If the mass of a black hole turned out to be more than 50 solar masses, then the foundations of stellar physics and stellar evolution would have to be revised. This time this did not happen, ”explained Elena Seifina, a leading researcher at the SAI MSU .
Previously, the Chinese discovered a dwarf radio galaxy with a large proportion of dark matter.