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Castor (in astronomy)

Castor (kăs´tər), bright star in the constellation Gemini; Bayer designation α Geminorum; 1992 position R.A. 7h34.1m, Dec. +31°54′. Slightly dimmer than Pollux, with which it forms the Twins, Castor has an apparent magnitude of 1.58, which still makes it one of the 25 brightest stars in the sky. Castor is actually a six-star system, being a visual triple each component of which is a binary star; the three components are an eclipsing binary and a pair of spectroscopic binaries. The two brightest components are white, main-sequence stars of spectral classes A1 and A5. The system is about 50 light-years distant.

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Castor

Cas·tor / ˈkastər/ 1. Greek Mythol. the twin brother of Pollux. See Dioscuri. 2. Astron. the second brightest star in the constellation Gemini, close to Pollux. It is a multiple star system, the three components visible in a moderate telescope being close binaries.

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"Castor." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"Castor." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/castor-0

"Castor." The Oxford Pocket Dictionary of Current English. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/castor-0

castor

castor 2 perforated vessel for sprinkling pepper, sugar, etc. XVII; swivel wheel on legs of furniture XVIII. var. of caster, agent-noun f. CAST + -ER 1. The sp. -or for -er (still current) may have been favoured as being more appropriate to an instrument; cf. razor, mirror, and words in -ATOR.

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"castor." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

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"castor." The Concise Oxford Dictionary of English Etymology. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/castor-3

castor

castor 1 beaver, unctuous substance obtained from the beaver (used as a drug). XIV. — (O)F. or L. castor — Gr. kástōr. The history of the use of castor oil (XVIII) for the pale-yellow oil obtained from the seeds of the plant Ricinus communis is obscure.

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castor

cas·tor / ˈkastər/ • n. a reddish-brown oily substance secreted by beavers, used in medicine and perfumes.

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"castor." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

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"castor." The Oxford Pocket Dictionary of Current English. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/castor-1

castor (in zoology)

castor: see beaver.

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castor

castorbarter, Bata, cantata, carter, cassata, charter, chipolata, ciabatta, darter, desiderata, errata, garter, imprimatur, Inkatha, Jakarta, Magna Carta, Maratha, martyr, Odonata, passata, persona non grata, rata, Renata, Río de la Plata, serenata, sonata, Sparta, starter, strata, taramasalata, tartar, Tatar, Zapata •after, drafter, grafter, hereafter, laughter, rafter, thereafter, whereafter •chanter, enchanter, granter, planter, supplanter, transplanter, Vedantablaster, caster, castor, faster, grandmaster, headmaster, master, pastor, plaster •alabaster • telecaster • forecaster •broadcaster • sportscaster •newscaster • sandblaster •bandmaster • taskmaster •pastmaster • paymaster • ringmaster •quizmaster • spymaster •housemaster • Scoutmaster •toastmaster • schoolmaster •harbourmaster (US harbormaster) •quartermaster • substrata •sought-after

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"castor." Oxford Dictionary of Rhymes. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

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"castor." Oxford Dictionary of Rhymes. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/castor