Hertzsprung-Russell diagram

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Hertz·sprung-Rus·sell diagram

 (hĕrts′sprŭng-rŭs′əl)
n.
A graph of the absolute magnitudes or luminosities of stars plotted against their surface temperatures or colors, used to classify stars by their evolutionary stages.

[After Ejnar Hertzsprung (1873-1967), Danish astronomer, and Henry Norris Russell.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Hertzsprung-Russell diagram

(ˈhɜːtssprʌŋˈrʌsəl)
n
(Astronomy) 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 graph. See also main sequence
[C20: named after Ejnar Hertzsprung and Henry Norris Russell]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

Hertz·sprung-Rus·sell diagram

(hĕrts′spro͝ong-rŭs′əl)
A graph of the natural brightness of stars plotted against their surface temperature or color. It is used in the study of the life cycles of stars.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
Janes and Sadia Hoq (Astronomical Journal, 2011) gives a color-magnitude diagram of King 9, which includes 497 stars within a 1 1/2' diameter that have a photometric membership probability of more than 50%.
Then they plotted the color and brightness of each star, resulting in a diagram referred to as a color-magnitude diagram. This diagram immediately tells astronomers a great deal about the evolutionary phase of the stars in the cluster.
Visually, 5053 could pass as a very rich open cluster, but its classification as a globular is supported by its color-magnitude diagram and by the presence of RR Lyrae variables, indicators of great age.
Geller and Mathieu studied 16 blue-straggler binaries in NGC 188, an open cluster 7 billion years old (judging by the pattern the rest of its stars make when plotted on a color-magnitude diagram).
Noting its peculiar color-magnitude diagram, Canadian astronomer Sydney van den Bergh hypothesized that NGC 1851 formed from the merger of two globular clusters that were once part of a dwarf spheroidal galaxy.
But the metallicity is always hard to estimate from a color-magnitude diagram, especially one as sparsely populated by stars as this one."
A user can, for example, create a color-magnitude diagram of all the Hipparcos stars, or selected subsets, such as the stars in the chosen field of view.
It wasn't until 1996 that a color-magnitude diagram finally revealed that IC 1257 is a distant, heavily reddened globular residing on the opposite side of the galaxy more than 80,000 light-years away.
The scientists then plotted a color-magnitude diagram for 50,000 of the cluster's stars.
Analyzing archival images taken with the Hubble Space Telescope's Wide Field and Planetary Camera 2, Burke and Mighell compared the Ursa Minor dwarf's color-magnitude diagram with that of M92, a 6th-magnitude globular cluster in Hercules.
Especially important are binaries in the Hyades; the color-magnitude diagram for this cluster is critical for calibrating the cosmic distance scale.