Astrophysics (Index)About

O-type star

(O, O-class star, O star)
(star with spectral characteristics of above 30000 K)

An O-type star (O) is a star within the O-class, a spectral class indicating stars with ionized helium absorption lines, a blue color, and a surface temperature above 30,000 K. The spectral energy distribution peaks in the XEUV range. Main sequence stars of this class are on the order of 50 solar masses, 10 solar radii, and 100,000 times solar luminosity. Such main sequence stars burn their hydrogen in a few million years. Characteristics of O-type main sequence stars:

-5 to -10absolute magnitude(bolometric)
10,000-1,000,000bolometric luminosity(solar)
2-9 million yearsmain-sequence lifetime
0.00002% to 0.00005%abundance

There are also giant stars and white dwarves that fall under the O-class. Examples of O-type stars are Mu Columbae (spectral type O9.5 V) and Mu Normae (spectral type O9.7Iab).

(star type,spectral class)
Further reading:
72.5nm4.2PHz17eVbeginO-type star
97nm3.1PHz13eVendO-type star

Referenced by pages:
Be star
convection zone
giant star
globular cluster (GC)
Galactic O Star Catalog (GOSC)
Gould's Belt
Markarian galaxy (Mkn)
solar mass (MSun)
O5 spectral type (O5)
OB association
OB star
rare designator prefixes
star formation rate (SFR)
shell star (sh)
superluminous supernova (SLSN)
solar wind
spectral class
star formation (SF)
stellar association
stellar demographics
stellar population
young stellar object (YSO)