- An extremely large red giant star with a minimum of 15 solar masses. The best known red supergiant is Betelgeuse, with a luminosity about 10,000 times that of the Sun. When a supergiant collapses into a supernova, it may result in either a neutron star or a black hole.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.