Stellar Luminsoity Classes

Class Description Typical Luminosity 
(solar luminosities)
Ia Bright supergiants 500,000
Iab Moderate supergiants 125,000
Ib Supergiants 8,000
II Bright giants 1,300
III Giants 100
IV Subgiants 25
V Main-sequence stars/dwarfs Entire range of values
White Dwarfs are not included in this system, but are usually denoted by a "D" - for example, DA indicates a white dwarf of spectral type A.