Astrophysics (Index)About

OB star

(a hot star with class O or early B)

The term OB star is for either an O-type star or a B-type star, generally used for 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 just this class. Stellar associations where they form and commonly live are called OB associations.

(star type)
Further reading:

Referenced by pages:
HII region (HII)
ionizing radiation
Case-Hamburg Survey (LS)
OB association
Strömgren sphere
T association
ultraviolet astronomy