luminosity
51Milky 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… …
52Star — For other uses, see Star (disambiguation) …
53Malmquist 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… …
54Cosmic 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… …
55galaxy — /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… …
56astronomy — /euh stron euh mee/, n. the science that deals with the material universe beyond the earth s atmosphere. [1175 1225; ME astronomie ( < AF) < L astronomia < Gk. See ASTRO , NOMY] * * * I Science dealing with the origin, evolution, composition,… …
57cosmos — /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… …
58White dwarf — For other uses, see White dwarf (disambiguation). Image of Sirius A and Sirius B taken by the Hubble Space Telescope. Sirius B, which is a white dwarf, can be seen as a faint pinprick of light to the lower left of the much brighter Sirius A …
59Relativistic beaming — Doppler beaming redirects here. For other uses named for Christian Doppler, see Doppler (disambiguation). Only a single jet is visible in M87. Two jets are visib …
60Megamaser — A megamaser is a type of astrophysical maser, which is a naturally occurring source of stimulated spectral line emission. Megamasers are distinguished from astrophysical masers by their large isotropic luminosity. Megamasers produce roughly 103… …
