Astrophysics (index)about

OB star

(a hot star with class O or early B)

The term OB star is used to designate a star that is either an O-type star or a B-type star, generally meaning just the early B stars. The term can be thought of as an alternate spectral classification consisting of the hottest stars, but a bit broader than just "O". Some star surveys cover this class. Stellar associations where they form and commonly live are called OB associations.

(star type,spectral type)

Referenced by:
HII region (HII)
OB association
Strömgren sphere