In astronomy, the term spectral type refers to the stellar magnitude of a star based on its temperature and color.
The sun Sigma Draconis was classified with a spectral type of Gamma 9. (TOS: "Spock's Brain")
Classification
The traditional classification scheme from hottest to coolest stars is:
- O-type star (blue in color) – FGC 1215 B, Mintaka A
- B-type star (blue-white to blue in color) – Vandor, Rigel
- In real life, unlike Vandor, no red giant can actually belong to type B, as B-type stars are exclusively blue or blue-white.
- A-type star (white to bluish white)– FGC 1215 A, Vega, Sirius
- F-type star (white)– Orellius Minor, Canopus
- G-type star (yellow) – Calindra, Hemikek, Sol
- K-type star (Orange in color) – Alpha Centauri B, Arcturus, Aldebaran
- M-type star (Red in color, includes red dwarf, red giant) – Proxima Centauri, 40 Eridani A, Betelgeuse