Where are the best candidates for black holes located?
Astronomers distinguish between two classes of black holes-stellar mass and supermassive. Stellar-mass black holes have masses from about 1 to 10 times the mass of the Sun and are the end products of the evolution of very massive stars. These are often found in binary star systems where they can be most easily detected as they affect the nearby star. Supermassive black holes contain millions or even billions of times the mass of the Sun and are found in the nuclei of galaxies and quasars, which the Hubble Space Telescope has confirmed in images, such as Plate 8, which shows the inner core of the quasar-like galaxy Messier 87 in the constellation Virgo. Table 10 is a list of the current suspected and confirmed black holes. Black holes are the least exotic explanation we can offer for some of the energetic things we are seeing in the universe. No other object has proven to be as helpful in accounting for the great variety of data now accumulated. We will never be able to actually see a b
