Scientists find closest star to the Milky Way's central black hole

Scientists have identified a star that is the closest known object to the Milky Way's supermassive black hole, Sgr A*. This discovery, detailed in the latest issue of Nature, could provide the first measurements of the black hole's spin. Known as Sgr A*, the black hole has been present at the center of the galaxy since at least the 1970s, but it has only recently been imaged.

Prior to this new star's discovery, astronomers primarily studied Sgr A* using the orbits of a group of stars that circle it, allowing them to estimate the black hole's mass and size. These stars have served as a unique tool for observing the otherwise inaccessible environment near the black hole. The newly discovered star is notable for its extremely eccentric orbit, which brings it closer to Sgr A* than any other object previously observed.

This proximity to the black hole presents a unique opportunity for scientists to gather data on the black hole's spin. By analyzing the star's mass, brightness, and spectral features, combined with its orbit reconstructed from years of data, researchers can estimate the supermassive nature of Sgr A* (approximately 10^37 kilograms).