According to a new study published in the Proceedings of the Japanese Academy of Sciences, a star near the supermassive black hole at the center of the Milky Way originated outside the Milky Way.
Many stars have been observed near the supermassive black hole at the center of the Milky Way galaxy known as Sagittarius A*. But the strong gravitational pull of a black hole makes the surrounding environment too harsh for stars to form near the black hole. All observed stars must have formed elsewhere and then migrated towards black holes. This raises the question: are stars formed?
Many stars have been observed near the supermassive black hole at the center of our galaxy called Sagittarius A*. But the strong gravitational pull of the black hole makes the surrounding environment too harsh for stars to form near the black hole. All observed stars must have formed elsewhere and migrated towards black holes. This raises the question: are stars formed?
Research suggests that some stars may have come from farther away than previously thought, completely outside the Milky Way. Over the course of eight years, the team used the Subaru telescope to observe Sagittarius A*, which is only 004 light-years star S0-6.
They determined that S0-6 is about 10 billion years old and has a chemical composition similar to that of stars found in small galaxies outside the Milky Way, such as the Small Small Magellanic Cloud and the Sagittarius Dwarf Galaxy.
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. This is the first observational evidence that some of the stars near Sagittarius A* formed outside the Milky Way.
In its 10 billion year lifespan, S0-6 must travel more than 50,000 light-years from outside the galaxy to reach the vicinity of Sagittarius A*. It is almost certain that the S0-6 flew well over 50,000 light-years, slowly circling down to the center rather than firing in a straight line.
Did S0-6 really originate beyond the galaxy? Does it have companions, or does it travel alone? Through further investigation, we hope to unravel the mysteries of the stars near the supermassive black hole.