A new study reveals that the star S0-6, located near the
Research Findings on Star S0-6
Research by an international team led by Shogo Nishiyama at Miyagi University of Education indicates the some of the stars may have come from farther away than previously thought, from completely outside of the Milky Way. The team used the Subaru Telescope over the course of eight years to observe the star S0-6 located only 0.04 light-years away from Sagittarius A*. They determined that S0-6 is about 10 billion years old and has a chemical composition similar to stars found in small galaxies outside the Milky Way, such as the Small Magellanic Cloud and the Sagittarius dwarf galaxy.
S0-6’s Galactic Journey
The most likely theory to explain the composition of S0-6 is that it was born in a now-extinct small galaxy orbiting the Milky Way that was absorbed. This is the first observational evidence suggesting that some of the stars in the vicinity of Sagittaius A* formed outside of the Galaxy. Over its 10 billion year life, S0-6 must have travelled more than 50,000 light-years from outside of the Milky Way to reach the vicinity of Sagittarius A*. Almost certainly S0-6 traveled much more than 50,000 light-years, slowly spiraling down to the center rather than making a straight shot.
Unanswered Questions and Future Research
There are still many questions according to Nishiyama, “Did S0-6 really originate outside the Milky Way galaxy? Does it have any companions, or did it travel alone? With further investigation, we hope to unravel the mysteries of stars near the supermassive black hole.”
Reference: “Origin of an orbiting star around the galactic supermassive black hole” by Shogo Nishiyama, Tomohiro Kara, Brian Thorsbro, Hiromi Saida, Yohsuke Takamori, Masaaki Takahashi, Takayuki Ohgami, Kohei Ichikawa and Rainer Schödel, 1 December 2023, Proceedings of the Japan Academy, Series B.
DOI: 10.2183/pjab.100.007