Stars orbiting supermassive black hole show Einstein was right again
(PHYSorg.com Space & Earth)

At the center of our galaxy, roughly 26,000 light years from Earth, lies the supermassive black hole (SMBH) known as Sagittarius A*. Measuring 44 million km across, this object is roughly 4 million times as massive as our Sun and exerts a tremendous gravitational pull. Since astronomers cannot detect black holes directly, its existence has been determined largely from the effect it has on the small group of stars orbiting it.