For the first time, a star from another galaxy has been discovered near the supermassive black hole at the center of the Milky Way. Based on eight years of observation data, scientists were able to determine the composition, speed and other parameters of this object.

Stars within 0.04 parsecs of stars near Sagittarius A* at the center of our galaxy are called S-stars by astronomers (not to be confused with S-type stars). They are divided into two groups: luminous B0-B3 main sequence stars with masses of eight to 14 solar masses and GM-class red giants with masses of 0.5 to two solar masses.

At the same time, the supermassive black hole at the center of the Milky Way has a mass of approximately 4.23 million solar masses. So stars are like particles, and you can learn a lot about Sagittarius A* from their motion.

These stars cannot form under gravitational conditions near such a powerful object. At the same time, as scientists assume, the stars of the second group (red giants) are probably very old. Therefore, today it is not possible to reconstruct their “journey” or understand where they came from just by movement. It is necessary to know its exact age and composition.

An international group of researchers led by Shogo Tishiyama from Miyagi University of Education (Japan) focused on the S-star S0-6 for this purpose. They observed it for eight years using the Subaru telescope. The results of the study were published at: Proceedings of the Japanese Academy.

The composition of S0-6 is different from the stars of the Milky Way, but similar to the stars of satellite galaxies: the dwarf elliptical galaxy in Sagittarius and the Large Magellanic Cloud. However, given the history of our Galaxy’s interaction with these objects, it is unlikely that the star formed there.

As the authors of the article note, recent research has shown that among the stars of the “nuclear” cluster of the Milky Way – as far as five parsecs from the center – there are objects that differ from the rest of the world. population of the galaxy”.

Presumably S0-6 was formed where the stars of this cluster are located – in some dwarf galaxy, which subsequently collapsed and “migrated” to the center of the Milky Way in the form of individual stars. It turned out that this star traveled at least 50 thousand light years in 10 billion years.