S62 (star)


S62 is a star in the cluster surrounding Sagittarius A*, the supermassive black hole in the center of the Milky Way.
In August 2019, S62 is the known star that circles Sgr A* the fastest. With an orbital period of only 9.9 years, it beats the previous record holder, the star S55, which circles Sgr A* in 12.8 years.
In addition, S62 has a very eccentric orbit which makes it pass very close to Sgr A*, only 16 astronomical units, less than the distance between Uranus and the Sun. The star therefore passes only about 215 times the Schwarzschild radius of Sgr A*. It is closer to Sgr A* than the previous record, around 45 AU held by the star S175, and much closer than the more well-studied S2.
S62 passes so close to Sgr A* that its orbit has a very large precession: its orbit shifts by about 10 degrees with each revolution. S62's next approach to Sgr A* is towards the end of 2022.
The discovery of S62 improved the bounds on the mass distribution in the center of the galactic center, showing that are concentrated within 16 AU of the center, fully compatible with Sgr A* being a supermassive black hole.