Hertzsprung-Russell diagram

[ hairt-sproong-ruhs-uhl ]
/ ˈhɛərt sprʊŋˈrʌs əl /

noun Astronomy.

the graph showing the absolute magnitude plotted against the surface temperature for a group of stars.



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Also called H-R diagram.

Origin of Hertzsprung-Russell diagram

after Danish astronomer Ejnar Hertzsprung (1873–1967) and H. N. Russell, who compiled the data on which it is based

Words nearby Hertzsprung-Russell diagram

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for Hertzsprung-Russell diagram

Hertzsprung-Russell diagram
/ (ˈhɜːtssprʌŋˈrʌsəl) /


a graph in which the spectral types of stars are plotted against their absolute magnitudes. Stars fall into different groupings in different parts of the graphSee also main sequence

Word Origin for Hertzsprung-Russell diagram

C20: named after Ejnar Hertzsprung and Henry Norris Russell
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for Hertzsprung-Russell diagram

Hertzsprung-Russell diagram

A graph in which the absolute magnitude (intrinsic luminosity) of stars is plotted vertically against their surface temperatures (or corresponding spectral types). The diagram shows a strong correlation between luminosity and surface temperature among the average-size stars known as dwarfs, with hot, blue stars having the highest luminosities and relatively cool, red stars having the lowest. The roughly diagonal line (running from the upper left of the diagram to the lower right) that shows this correlation is called the main sequence. Giant and supergiant stars have relatively high luminosities for their surface temperatures and are positioned on the diagram above the main sequence. The faint white dwarfs have relatively low luminosities for their surface temperatures and cluster below the main sequence. See more at main sequence.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.