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 (hypergiant) – FGC-1215 B, Mintaka
- B-type star ("blue giants" and some red giants) – Vandor, Rigel
- In real life, no red giant can actually belong to type B, as B-type stars are exclusively blue.
- A-type star – FGC-1215 A, Vega, Sirius
- F-type star – Orellius Minor, Canopus
- G-type star (yellow dwarf) – Calindra, Hemikek, Sol
- K-type star – Alpha Centauri B, Arcturus, Aldebaran
- M-type star (red dwarf, red giant) – Proxima Centauri, 40 Eridani A, Betelgeuse