The discoveries will bring the total number of black holes so far found in the universe to at least 33. Jr. Centennial Chair in Astronomy at UT Austin's department of astronomy, Dr. Karl Gebhardt, a Hubble post-doctoral fellow at the University of California at Santa Cruz, Dr. Douglas Richstone, a professor of astronomy at the University of Michigan department of astronomy and an international team of collaborators. In the early days of the search, from the late 1980s through the mid-1990s, all the emphasis was on finding out whether these black holes really exist. Black holes are celestial bodies that are so compressed their surface gravity is strong enough to keep even light from escaping.
Some black holes have masses several times the mass of the Earth's Sun.
These black holes are formed when massive stars die. Supermassive black holes, in contrast, are a million to a billion times the mass of the Sun and are found at the centers of galaxies. Because they are invisible, scientists can only detect and study black holes by observing the movements and velocities of the stars swirling around them. The first supermassive black hole was discovered in 1984, although astrophysicists for years had been predicting black holes based on their theories of how the galaxies operate. Supermassive black holes were predicted by our theory of what powers quasars, the brightest objects in the universe.