Image: Hertzsprung-russel diagram

Description: This is an example of a Hertzsprung-Russell diagram; a plot of luminosity versus spectral class for a group of stars. The diagonal band labelled "main sequence" is where dwarf stars such as the Sun spend most of their active lifespan. Red giants and supergiants are evolved stars with a mass greater than a red dwarf, that are burning elements heavier than hydrogen. However, White Dwarfs are quite dense, non-luminous, but are still less in mass than supergiants. Once this supply of fuel is exhausted, these stars will migrate to the lower left on this diagram, becoming white dwarfs.
Title: Hertzsprung-russel diagram
Credit: This illustration by the contributor is based on Figure 3 (p. 52) of Great Ideas and Theories of Modern Cosmology by Jagjit Singh.[1]
Author: Illustraion by R.J. Hall
Usage Terms: Creative Commons Attribution 2.5
License: CC BY 2.5
License Link: http://creativecommons.org/licenses/by/2.5
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