- luminosity class
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a classification of stars of a given spectral type according to their luminosity, breaking them down into dwarfs, giants, and supergiants.
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Universalium. 2010.
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Universalium. 2010.
luminosity class — Astron. a classification of stars of a given spectral type according to their luminosity, breaking them down into dwarfs, giants, and supergiants … Useful english dictionary
Luminosity — has different meanings in several different fields of science.In photometry and color imagingIn photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI… … Wikipedia
spectral class — noun A classification of stars depending on their spectra and luminosity; usually one of O, B, A, F, G, K, M … Wiktionary
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
Stellar classification — In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are… … Wikipedia
cosmos — /koz meuhs, mohs/, n., pl. cosmos, cosmoses for 2, 4. 1. the world or universe regarded as an orderly, harmonious system. 2. a complete, orderly, harmonious system. 3. order; harmony. 4. any composite plant of the genus Cosmos, of tropical… … Universalium
galaxy — /gal euhk see/, n., pl. galaxies. 1. Astron. a. a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of space. b. (usually cap.) See Milky Way. 2. any large and brilliant or impressive… … Universalium
star — starless, adj. /stahr/, n., adj., v., starred, starring. n. 1. any of the heavenly bodies, except the moon, appearing as fixed luminous points in the sky at night. 2. Astron. any of the large, self luminous, heavenly bodies, as the sun, Polaris,… … Universalium
Star — For other uses, see Star (disambiguation) … Wikipedia
Variable star — A star is classified as variable if its apparent brightness as seen from Earth changes over time, whether the changes are due to variations in the star s actual luminosity, or to variations in the amount of the star s light that is blocked from… … Wikipedia