Noun
Hertzsprung-Russell diagram (plural Hertzsprung-Russell diagrams)
(astronomy) A graphic representation of the absolute magnitude of stars against their color (or surface temperature), which shows the main sequence of stars plus the white dwarfs and red giants.
Accurate knowledge of the distance allows astronomers to plot a Hertzsprung-Russell diagram for the cluster, which, when compared to those plotted for clusters whose distance is not known, allows their distances to be estimated. Source: Internet
Because the Hertzsprung-Russell diagram is observational in nature, these remnants cannot easily be plotted on the diagram, or cannot be placed at all. Source: Internet
In 1913, the Hertzsprung-Russell diagram was developed, propelling the astrophysical study of stars. Source: Internet