Hertzsprung–Russell diagram


Hertzsprung–Russell diagram

 in astronomy, graph in which the absolute magnitudes (intrinsic brightness) of stars are plotted against their spectral types. Of great importance to theories of stellar evolution, it evolved from charts begun in 1911 by the Danish astronomer Ejnar Hertzsprung (Hertzsprung, Ejnar) and independently by the U.S. astronomer Henry Norris Russell (Russell, Henry Norris).

      On the diagram stars are ranked from bottom to top in order of decreasing magnitude (increasing brightness) and from right to left by increasing temperature (spectral class). Stars of the galactic arm in which the Sun is located tend to fall into distinct regions on the diagram. The group called the main sequence extends in a rough diagonal from the upper left of the diagram (hot, bright stars) to the lower right (dim and cool). The giant sequence of large, bright, though cool, stars appears in the upper right, and the white dwarfs, dim, small, and hot, lie in the lower left. The Sun lies near the middle of the main sequence.

      Diagrams drawn for the same stars with colour instead of temperature plotted against magnitude give similar results and are called colour–magnitude diagrams (colour–magnitude diagram). Colour–magnitude diagrams drawn for stars from other parts of the Milky Way Galaxy—e.g., globular clusters—show different patterns from that for the local stars.

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Universalium. 2010.

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  • Hertzsprung–Russell diagram — Hertzsprung–Russell diagram[1] with 22,000 stars plotted from the Hipparcos catalog and 1,000 from the Gliese catalog of nearby stars. Stars tend to fall only into certain regions of the diagram. The most predominant is the diagonal, going from… …   Wikipedia

  • Hertzsprung-Russell diagram — The Hertzsprung Russell diagram (usually referred to by the abbreviation H R diagram or HRD, also known as a colour magnitude diagram, or CMD) shows the relationship between absolute magnitude, luminosity, classification, and effective… …   Wikipedia

  • hertzsprung-russell diagram — ˈhertˌspru̇ŋˈrəsəl noun Usage: usually capitalized H&R Etymology: after Ejnar Hertzsprung died 1967 Dan. astronomer and Henry Norris Russell died 1957 American astrophysicist : spectrum luminosity diagram * * * /hairt sproong rus euhl/, Astron.… …   Useful english dictionary

  • Hertzsprung-Russell diagram — /hairt sproong rus euhl/, Astron. the graph showing the absolute magnitude plotted against the surface temperature for a group of stars. Also called H R diagram. [after Danish astronomer Ejnar Hertzsprung (1873 1967) and H. N. RUSSELL, who… …   Universalium

  • Hertzsprung-Russell diagram — /ˌhɜtsprʌŋ ˌrʌsəl ˈdaɪəgræm/ (say .hertsprung .rusuhl duyuhgram) noun a graph in which the absolute luminosity of a star is plotted against its spectral type (an indication of its temperature). The theory of stellar evolution has been derived… …   Australian English dictionary

  • Hertzsprung-Russell diagram — noun a plot of the absolute magnitude of stars versus their colour (or surface temperature); shows the main sequence of stars plus the white dwarfs and red giants …   Wiktionary

  • Hertzsprung - Russell diagram — …   Useful english dictionary

  • Hertzsprung–Russell diagram — …   Useful english dictionary

  • Hertzsprung-Russell diagrammet — Diagram som viser sammenhængen mellem stjernernes spektraltype og absolutte lysstyrke …   Danske encyklopædi

  • Russell — is an English, Irish, or Scottish name derived from old French, the old French word for Red was rouse ; hence the carry over from French the English Russell, the name also derives from the animal, the fox. Its uses include:People*Arthur Russell… …   Wikipedia


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