Peering deep into the heart of our Milky Way galaxy, NASA’s Hubble Space Telescope reveals a rich tapestry of more than half a million stars. Except for a few blue foreground stars, the stars are part of the Milky Way’s nuclear star cluster, the most massive and densest star cluster in our galaxy. So packed with stars, it is equivalent to having a million suns crammed between us and our closest stellar neighbor, Alpha Centauri. At the very hub of our galaxy, this star cluster surrounds the Milky Way’s central supermassive black hole, which is about 4 million times the mass of our sun.
http://www.nasa.gov/feature/goddard/2016/hubble-s-journey-to-the-center-of-our-galaxy
