The Max Planck Institute for Extraterrestrial Physics, and the UCLA Galactic Center Group, have provided strong evidence that Sagittarius A* is the site of a supermassive black hole. This is based on data from the ESO, and the Keck telescope. Our galactic central black hole is calculated to have a mass of approximately 4.1 million solar masses, or about 8.2 × 10 kg.