In space, most orbiting objects will have circular- or elliptical-shaped orbits. But now, almost 30 years of observations has revealed that a star in the center of our galaxy orbits the supermassive black hole Sagittarius A* (Sgr A*) in a rosette, or spirograph shape. The find once again confirms a prediction made by Einstein’s General Relativity.
But things are very different for S2. This star orbits the supermassive black hole at the heart of the Milky Way on an oval-shaped path – but the oval isn’t centered on the black hole. Instead, it’s located at one end. Thanks to the extremely powerful gravitational pull of Sgr A*, S2 speeds up as it falls towards the black hole, before it’s slingshotted away, slows back down, and is eventually pulled back towards the black hole.
Astronomers have been studying S2 for decades, and its unusual orbit was actually one of the first compelling pieces of evidence that there is a supermassive black hole at the center of the Milky Way.