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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or North Star

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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