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 (SED) 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:

9.5-16radius(solar)
16-100+mass(solar)
-5 to -10absolute magnitude(bolometric)
10,000-1,000,000bolometric luminosity(solar)
1-10 million yearsmain-sequence lifetime
0.00002% to 0.00005%abundance

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


(star type,spectral class)
Further reading:
https://en.wikipedia.org/wiki/Stellar_classification#Class_O
https://en.wikipedia.org/wiki/O-type_star
https://en.wikipedia.org/wiki/O-type_main-sequence_star
https://en.wikipedia.org/wiki/Blue_giant
https://en.wikipedia.org/wiki/Blue_supergiant_star
https://lweb.cfa.harvard.edu/~pberlind/atlas/htmls/ostars.html
http://hyperphysics.phy-astr.gsu.edu/hbase/Starlog/staspe.html#c2
https://www.daviddarling.info/encyclopedia/O/Ostar.html
http://www.peripatus.gen.nz/Astronomy/SpeTypeO.html
WaveLFreqPhoton
Energy
  
72.5nm4.2PHz17eVbeginO-type star
97nm3.1PHz13eVendO-type star

Referenced by pages:
Be star
Eta Carinae (η Car)
Galactic O Star Catalog (GOSC)
globular cluster (GC)
Gould's Belt
helium star
hypergiant
Markarian galaxy (Mkn)
O5 spectral type (O5)
OB association
OB star
Orion
Population I (Pop I)
Population II (Pop II)
PSR B1259-63
rare designator prefixes
shell star (sh)
solar mass (MSun)
spectral class
spectral type
star formation (SF)
star formation rate (SFR)
stellar association
stellar demographics
stellar population
stellar wind
supergiant
superluminous supernova (SLSN)
WR 140
young stellar object (YSO)

Index