There are two spectral subclasses of Wolf-Rayets: type WN, which have prominent emission lines of helium and nitrogen, and type WC in which carbon, oxygen and helium lines dominate.
A Wolf-Rayet phase is also present in some central stars of planetary nebulae. In these stars, which have lower masses and will evolve into white dwarfs, the outer envelope has been expelled in the red giant phase, exposing the hot core. Such stars show many of the characteristics of standard Wolf-Rayet stars and are referred to as Wolf-Rayet type stars.
The best known and probably the closest Wolf-Rayet star to Earth is one of the components of the Gamma Velorum star system.
*This figure refers to the mass with which the star begins its life. It may lose about three-quarters of this initial mass during its Wolf-Rayet phase.
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact