Hertzsprung-Russell diagram

American  

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

noun

Astronomy.

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

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Hertzsprung-Russell diagram British  

/ ˈhɜːtssprʌŋˈrʌsəl /

noun

1. 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

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Hertzsprung-Russell diagram Scientific  

1. 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.

2. See more at main sequence

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Etymology

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

Example Sentences

Their extreme nature marks them as celestial outcasts that cluster at the borders of astronomy's foundational chart, the Hertzsprung-Russell diagram, which maps stars by their brightness and temperature.

From Scientific American

Animals and plants fall into phylogenetic trees, minerals into crystal groups, elements into the periodic table, stars into the Hertzsprung-Russell diagram.

From Economist

Instead of a final paper, she submitted a woven basket that was her 3-D translation of the Hertzsprung-Russell diagram, a scatter graph used to track evolutionary stages of stars by luminosities, among other things.

From New York Times