Stellar Classification

Patrick Greenwell

Randy McCullick

Revision History
Revision 1 9 Jaunary 2004

Approved by Assistant GM Director Robert Gulley


Table of Contents

Stellar Classes
Class O
Class B
Class A
Class F
Class G
Class K
Class M
Stellar Class Subdivisions

Stellar Classes

Class O

Examples

Mintaka (Delta Orionis)

Color

Dark Blue

Temperature

28,000 to 50,000 Kelvin

Composition

Ionized atoms, especially helium

Class B

Examples

Rigel, Spica

Color

Blue

Temperature

10,000 to 28,000 Kelvin

Composition

Neutral Helium, some hydrogen

Class A

Examples

Sirus A

Color

Light Blue

Temperature

7,500 to 10,000 Kelvin

Composition

Strong hydrogen, some ionized metals

Class F

Examples

Procyon A

Color

White

Temperature

6,000 to 7,000 Kelvin

Composition

Hydrogen and ionized metals, calcium and iron

Class G

Examples

Sol

Color

Yellow

Temperature

5,000 to 6,000 Kelvin

Composition

Ionized Calcium, both neutral and ionized metals

Class K

Examples

Alpha Centauri B, Arcturus

Color

Orange

Temperature

3,500 to 5,000 Kelvin

Composition

Neutral metals

Class M

Examples

Wolf 359, Betelgeuse

Color

Red

Temperature

2,500 to 3,500 Kelvin

Composition

Ionized atoms, especially helium

Stellar Class Subdivisions

Each star class is divided into 10 subclasses, ranging from 0 (hottest) to 9 (coolest). Stars are also divided into six categories according to luminosity:

Example: Earth's star, Sol would be rated as a G2V, which means that it is a relatively hot (2) G-Class (G) main sequence star (V). So when naming the sub-class of a star they should be named in the following format:

[Letter of class][Temperature number 0 to 9][Luminosity category]

Note

Classes R, N, S, T, Q, and W are not in the main sequence above. They are used for rare star types. More information on these classes will be listed if/when it becomes available in later Paramount-approved products or episodes