Astrophysics (Index)About


(supergiant star)
(very large giant star)

Supergiant (or supergiant star) is a term generally used for a very bright giant star. Such stars are post-main-sequence stars that were massive and hot during their main-sequence, e.g., O-type stars. The term generally means brighter than a bright giant. The very brightest supergiants are termed hypergiants. The term supergiant is not consistently defined, but is applied to stars in this general range:

-3 to -8 absolute magnitude
1000-1000000 × solar luminosity
30-1000 × solar
or 0.1-5 AU
8-12 × solar mass
3500-20000 K temperature

Since brightness is the criteria, the radii can overlap with "non-super giant" stars. Qualifications used for some of the brightest:

Supergiants can be of various spectral classes and can be red, blue, or yellow. Examples of supergiants:

Blue supergiant characteristics:

10000-1000000 × solar luminosity
10000-50000 K temperature

They are post-main-sequence OB stars.

An extreme helium star (EHe) is a rare type of supergiant nearly devoid of hydrogen. Their formation is a topic of research interest.

(star type,stellar evolution)
Further reading:

Referenced by pages:
A-type star (A)
BA supergiant
B-type star (B)
flux-weighted gravity-luminosity relationship (FGLR)
G-type star (G)
giant star
instability strip
K-type star (K)
luminosity class
M-type star (M)
pulsating star
red supergiant cluster (RSGC)
spectral type
Thorne-Żytkow object (TZO)
variable star