main sequence
main sequence main" se`quence, n. (Astronomy) That region on a two-dimensional graph of luminosity versus temperature for stars (the Herzsprung-Russel diagram), which runs from high temperature and high luminosity to low temperature and low luminosity, in which most of the stars (plotted as points on the diagram) are found. A normal star such as the earth's sun will spend most of its time over billions of years within this region of temperature and luminosity, as it progressively converts more of its original hydrogen into heavier elements. After the hydrogen is consumed, a star may become a {red giant} or evolve into other types of star not within the main sequence region. [PJC]

The Collaborative International Dictionary of English. 2000.

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  • Main sequence — A Hertzsprung Russell diagram plots the actual brightness (or absolute magnitude) of a star against its color index (represented as B V). The main sequence is visible as a prominent diagonal band that runs from the upper left to the lower right.… …   Wikipedia

  • main sequence — noun a) A major grouping of stars that creates a narrow band from the upper left to the lower right when plotted by luminosity and surface temperature on a Hertzsprung Russell diagram. b) The area on the Hertzsprung Russell diagram in which the… …   Wiktionary

  • main sequence — noun Date: 1925 the group of stars that on a graph of spectrum versus luminosity forms a band comprising 90 percent of stellar types and that includes stars representative of the stages a normal star passes through during the majority of its… …   New Collegiate Dictionary

  • main sequence — Astron. a narrow band in the Hertzsprung Russell diagram in which 90 percent of all observed stars are plotted. [1925 30] * * * …   Universalium

  • main-sequence — adjective Of or dealing with a major group of stars forming a band stretching from upper left to lower right on a Hertzsprung Russell diagram when being plotted by luminosity and surface temperature …   Wiktionary

  • main sequence — noun Astronomy a series of types to which most stars other than giants, supergiants, and white dwarfs belong. Origin 1920s: so named because they occupy a broad band on a graph of magnitude against spectral type …   English new terms dictionary

  • main sequence — noun : the broad band of the spectrum luminosity diagram which contains the great majority of stars and the sun and for which the absolute visual magnitudes range from about 3 for stars of spectral type B to 12 for stars of spectral type M …   Useful english dictionary

  • main-sequence star — /meɪn sikwəns ˈsta/ (say mayn seeksuhns stah) noun Astronomy any of the stars which form the main band in the Hertzsprung Russell diagram, whose energy comes from nuclear fission as they convert hydrogen to helium, the sun being one example …   Australian English dictionary

  • Main Sequence Stars —    A grouping of stars on the Hertzsprung Russell diagram that contains most stars. This grouping runs diagonally from the upper left of the chart to the lower right …   The writer's dictionary of science fiction, fantasy, horror and mythology

  • K-type main-sequence star — Hertzsprung–Russell Diagram Spectral Type Br …   Wikipedia

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