Stellar Classes

O-Type

O-Type star (STSC)

**Dark Blue^[1]**
Temperature	28,000-50,000°K
Composition	Ionized atoms, especially helium
Example	Mintaka (O1-3III)

B-Type star (STSC)

**Blue^[1]**
Temperature	10,000-28,000°K
Composition	Neutral helium, some hydrogen
Example	Alpha Eridani A (B3V-IV)

A-Type star (STSC)

**Light Blue^[1]**
Temperature	7,500-10,000°K
Composition	Strong hydrogen, some ionized metals
Example	Sirius A (A0-1V)

F-Type star (STSC)

**White^[1]**
Temperature	6,000-7,500°K
Composition	Hydrogen and ionized metals, calcium and iron
Example	Procyon A (F5V-IV)

**Yellow^[1]**
Temperature	5,000-6,000°K
Composition	Ionized calcium, both neutral and ionized metals
Example	Sol (G2V)

K-Type star (STSC)

M-Type star (STSC)

**Red^[1]**
Temperature	2,500-3,500°K
Composition	Ionized atoms, especially helium
Example	Wolf 359 (M5-8V)

**References**
↑ ^{Jump up to: 1.0} ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 ^1.6 "Star Trek: Star Charts." Star Trek. Book. Pocket Books. October 2002.