Stars in the Center of the Milky Way

Image Source: http://www.astro.ucla.edu/~ghezgroup/gc/pictures/lgs05.shtml

This infrared image shows the star cluster at the center of our Milky Way galaxy. At the center of the field is the location of a supermassive black hole (not visible). While some of the brighter stars are in the foreground, many of the faint ones seen here are 27,000 light years away at the galaxy's center

Some of the stars around the central black hole orbit so quickly that their motions can be seen from year to year. Their fast orbits are a consequence of the immense gravity of the black hole, which is about 4 billion times stronger than that of the Sun.