Blue supergiant

A blue supergiant (BSG) is a hot, luminous star, also called an OB supergiant. They are usually thought to be those with luminosity class I and spectral class B9 or earlier, although sometimes A-class supergiants are also called blue supergiants.

They are bigger than the Sun but smaller than a red supergiant, with surface temperatures of 10,000–50,000 K and luminosities from about 10,000 to a million times that of the Sun. They might form when two stars merge together. 

 Related pages 

 Red supergiant
 Supergiant
 Luminosity

 References 

Category:Stars
Category:Types of stars