luminosity function
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Luminosity function — The luminosity function or luminous efficiency function describes the average sensitivity of the human eye to light of different wavelengths. It should not be considered perfectly accurate in every case, but it is a very good representation of… … Wikipedia
Luminosity function (astronomy) — In astronomy, the luminosity function gives the number of stars or galaxies with a given luminosity. [ [http://www.daviddarling.info/encyclopedia/L/lumfunc.html luminosity function] , David Darling, entry in The Internet Encyclopedia of Science … Wikipedia
Planetary nebula luminosity function — (PNLF) is a secondary distance indicator used in astronomy. It makes use of the [O III| [O III] λ5007 forbidden line found in all planetary nebula which are members of the old stellar populations (Population… … Wikipedia
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
Initial mass function — The initial mass function (IMF) is an empirical function that describes the mass distribution (the histogram of stellar masses) of a population of stars in terms of their theoretical initial mass (the mass they were formed with). The properties… … Wikipedia
Milky Way Galaxy — Large spiral galaxy (roughly 150,000 light years in diameter) that contains Earth s solar system. It includes the multitude of stars whose light is seen as the Milky Way, the irregular luminous band that encircles the sky defining the plane of… … Universalium
Malmquist bias — For other uses of Malmquist, see Malmquist (disambiguation). The Malmquist bias refers to an effect in observational astronomy which leads to the preferential detection of intrinsically bright objects. It was first popularized in 1922 by Swedish… … Wikipedia
Cosmic distance ladder — * Light green boxes: Technique applicable to star forming galaxies. * Light blue boxes: Technique applicable to Population II galaxies. * Light Purple boxes: Geometric distance technique. * Light Red box: The planetary nebula luminosity function… … Wikipedia
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
Extragalactic distance scale — The extragalactic distance scale is a series of techniques used today by astronomers to determine the distance of cosmological bodies (beyond our own galaxy) not easily obtained with traditional methods. Some procedures utilize properties of… … Wikipedia
