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Cepheid variable |
Also found in: Dictionary/thesaurus, Wikipedia, Hutchinson | 0.04 sec. |
Cepheid variableOne of a class of variable stars whose period of variation is closely related to its luminosity and is therefore useful in measuring the distances to clusters of stars and galaxies. Named for the prototype of this class found in the constellation Cepheus, classical Cepheids have periods from about 1.5 days to over 50 days and are Population I stars (see Populations I and II). The longer the period of such a star, the greater its natural brightness; this relationship was discovered in 1912 by the American astronomer Henrietta Leavitt (b. 1868—d. 1921). How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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Polaris is the nearest known Cepheid variable, a type of star used to measure the distances to other galaxies and the rate of expansion of the universe. In 1923, while observing the Andromeda nebula, he found that it contained a Cepheid variable, a star that regularly varies in brightness. used the Hubble Space Telescope to observe about 24 of the stars known as Cepheid variables. |
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Cepheid variable
