2023-12-05 10:45:09
A surprising discovery has baffled the scientific community. In the central region of our galaxy, near the supermassive black hole of the galactic nucleus, there is a star that did not form in our galaxy but in another.
It is the first time that a star of extragalactic origin has been found so far into the galactic nucleus.
Many stars are observed near the supermassive black hole known as Sagittarius A*, at the center of our Milky Way galaxy. But the black hole’s intense gravity makes the environment unsuitable for stars to form there. All the stars observed must have formed somewhere else and migrated towards the neighborhood of the black hole. Until now, it was believed that they formed in a region not far from there, within our galaxy.
The discovery made by the international team of Shogo Nishiyama, from the Miyagi University of Education in Japan, indicates that some of the stars came from further away than previously thought, in some cases from outside the Milky Way.
The team used the Subaru telescope several times over eight years to observe the star S0-6, located just 0.04 light-years from Sagittarius A*. They determined that the age of S0-6 is about 10 billion years and that the star has a chemical composition similar to that of stars in small galaxies in the neighborhood of the Milky Way, such as the Small Magellanic Cloud and the dwarf galaxy. Sagittarius.
The central region of the Milky Way captured by the Subaru telescope. The image shows many stars in a field of view about 0.4 light-years across. The star S0-6 (blue circle), the subject of this study, is located about 0.04 light-years from the supermassive black hole Sagittarius A* (Sgr A*, green circle). (Image: Miyagi University of Education/NAOJ)
The most likely theory to explain the composition of S0-6 is that it was born in a small, now extinct galaxy that orbited the Milky Way and was absorbed by it.
What was achieved in the new study constitutes the first observational evidence that one (and probably others) of the stars closest to Sagittarius A* were formed outside the galaxy. Throughout its 10 billion years of life, S0-6 must have traveled more than 50,000 light-years from outside the Milky Way to reach the vicinity of Sagittarius A*.
The study is titled “Origin of an Orbiting Star around the Galactic Supermassive Black Hole.” And it has been published in the academic journal Proceedings of the Japan Academy Series B. (Source: NCYT from Amazings)
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