What is a Supergiant Star?
Supergiants are stars with between 10 and 70 solar masses. They are among the most massive stars known, located at the top of the Hertzsprung-Russell diagram, which maps star luminosity against spectral type. Like most other star types, supergiants come in all colors: red supergiants, blue supergiants, yellow supergiants, etc. They live fast (10-50 million years) and die hard (forming a black hole or neutron star after a supernova). Stars even more massive than supergiants, in the range of 70 to 120 solar masses, are called hypergiants. Stars much more massive than 120 solar masses cannot exist because they blow themselves apart with nuclear reactions before they can fully form. The more massive a star is, the more intense its solar wind is, and the more of its mass it loses. The short-lived and very massive Wolf-Rayet supergiant stars are the most intense cosmic geysers known, ejecting 10-3% of their mass into the interstellar medium each year at speeds of up to 2000 km/s. Because the
