A mystery star located at the heart of the Milky Way could very well be from another galaxy, new research shows. The star is known as an S-star, and it is part of a swarm of stars found near Sagittarius A*, our galaxy’s supermassive black hole.
These S-stars are located within a region of space around the supermassive black hole that is thought to be too extreme and messy to allow for any new star formation. As such, stars found within this region of space are often believed to have come from somewhere else. In this case, a group of researchers believe mystery star S0-6 may have come from an alien galaxy.
S0-6 is, of course, just one of several mystery stars found near the center of the Milky Way, and astronomers have long puzzled over where these stars came from, and how they survive the messy space around black holes like Sagittarius A*. The researchers spent eight long years studying S0-6, noting down its trajectory, velocity, and even finding acceleration that confirms its orbit around our supermassive black hole.
Using careful analysis of the light emitted by the star, the researchers were able to determine that this particular Milky Way mystery star did not come from around here. Instead, its chemical composition matches those of stars found outside of the Milky Way from the same time period — roughly 10 billion years ago.
It isn’t unlikely or unexpected to see a star that isn’t from the Milky Way hanging around in the center of our galaxy. After all, the Milky Way has existed for over 13 billion years, and in that time, the galaxy has eaten up several other, smaller galaxies and continues to do so today. Sometime in the future, astronomers believe our own Milky Way galaxy will meet up with the Andromeda galaxy, and end with the two merging together.
The researchers say that they hope to unravel the true origins of the mystery star S0-6 and that future analysis should hopefully provide more information. A paper on the recent discovery can be found in Proceedings of the Japan Academy, Series B.
