Polaris

Polaris
/poh lair"is, -lar"-, peuh-/, n.
1. Astron. the polestar or North Star, a star of the second magnitude situated close to the north pole of the heavens, in the constellation Ursa Minor: the outermost star in the handle of the Little Dipper.
2. a two-stage U.S. ballistic missile, usually fired from a submerged submarine.
[1955-60; short for ML stella polaris polar star]

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Earth's present northern polestar (the star visible from the Northern Hemisphere toward which Earth's axis points), at the end of the "handle" of the Little Dipper in the constellation Ursa Minor.

Polaris is actually a triple star, composed of a binary star and a Cepheid variable. Precession of Earth's axis made the star Thuban, in the constellation Draco, the North Star in ancient Egyptian times; it will cause the North Pole to point toward Vega, in the constellation Lyra, 12,000 years from now.

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star
also called  Alpha Ursae Minoris 

      Earth's present northern polestar, or North Star, at the end of the “handle” of the so-called Little Dipper in the constellation Ursa Minor. Polaris is actually a triple star, the brighter of two visual components being a spectroscopic binary with a period of about 30 years and a Cepheid variable with a period of about 4 days. Its changes in brightness are too slight to be detected with the unaided eye. Apparent visual magnitude of the Polaris system is 2.00. See also polestar.

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Universalium. 2010.

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  • POLARIS — «POLARIS» Год основания 1998 Расположение …   Википедия

  • Polaris — steht für: den astronomischen Namen des Polarsterns Polaris Industries, amerikanischer Fahrzeughersteller UGM 27 Polaris, Mittelstreckenrakete der USA und Großbritanniens Polaris (Schiff), Forschungsschiff des Polarforschers Charles Francis Hall… …   Deutsch Wikipedia

  • Polaris — puede referirse a: ● Polaris en astronomía, estrella normalmente conocido como la Estrella del Norte (Polaris Borealis). ● Polaris Australis estrella que es actualmente la Estrella del Sur, Sigma Octantis. ● UGM 27 Polaris Submarino diseñado por… …   Enciclopedia Universal

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  • Polaris — Modern Latin, short for stella polaris, lit. the pole star (see POLAR (Cf. polar)). The ancient Greeks called it Phoenice, the Phoenician (star), since the Phoenicians used it for navigation, though due to precession of the equinoxes it was not… …   Etymology dictionary

  • Polaris — [pō lar′is] n. [ModL < ML (stella) polaris, polar (star): see POLE2] a binary Cepheid variable, the brightest star in the constellation Ursa Minor; North Star; Pole Star: magnitude, 1.95 to 2.05: used for navigation, since it is the closest… …   English World dictionary

  • Polaris — Po*la ris, n. [NL. See {Polar}.] (Astron.) The polestar. See {North star}, under {North}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Polaris — Polaris,   1) Astronomie: der Polarstern.    2) Militärwesen: Mitte der 1960er Jahre zunächst in den USA, dann auch in Großbritannien eingeführte U Boot gestützte nukleare Mittelstreckenrakete; in den USA bis 1982 außer Dienst gestellt, in… …   Universal-Lexikon

  • Polaris — Starbox begin name=Alpha Ursae Minoris Starbox image caption=Polaris as seen by the Hubble Space Telescope. Starbox observe epoch=J2000 ra=02h 31m 48.7s dec=+89° 15 prime; 51 Prime; appmag v=1.97 constell=Ursa Minor Starbox character class=F7 Ib… …   Wikipedia

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