Astrophysics (index)about

Luminosity Class

(Morgan-Keenan Luminosity Class, MK Luminosity Class, MK Class)
(classification of size/luminosity of stars)

A star's Luminosity Class (or Morgan-Keenan Luminosity Class or MK Luminosity Class or MK Class) is a classification (Star Class) of the overall size of a star (as are terms like Giant Star, Supergiant, etc.) which is a major contributor to its Luminosity. A description of a star might include its Spectral Class and Luminosity Class. The general classifications are indicated by Roman numerals:

Additional classification:

  • Ia-O - Extreme Luminous Supergiants.
  • Ia - Luminous Supergiants.
  • Ib - less luminous supergiants.
  • D - White Dwarves.