pole star

North Star, star above the North Pole

A pole star is a visible star that is approximately aligned with the Earth's axis of rotation; that is, a star that lies in the direction pointed to by one of Earth's poles. There are potentially both  north  and south pole stars, but whether there is either depends on the current stellar configuration. The term the pole star usually refers to the star Polaris (colloquially referred to as the "north star") which is the current northern pole star.
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Polaris (α UMi / α Ursae Minoris / Alpha Ursae Minoris), more commonly known as The North Star or simply North Star, is the brightest star in the constellation Ursa Minor. It is very close to the north celestial pole (42′ away  as of 2006), making it the current northern pole star.
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In astronomy, Polaris is a star more commonly known as the North Star.
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Noun
1. the brightest star in Ursa Minor; at the end of the handle of the little dipper; the northern axis of the earth points toward it
(synonym) Polaris, North Star, polar star, polestar
(hypernym) variable star, variable
(member-holonym) Little Bear, Ursa Minor

Pole Star The north star, alpha polaris in the constellation of Ursa Minor, is within 1½ degrees of the north pole of the celestial sphere, to which the north end of the earth's axis points. This point is therefore the center around which the other constellations, in their daily apparent motion, revolve. The precession of the equinoxes shifts the position of the celestial north pole in a cycle of about 26,000 years, to a maximum extent of about 47 degrees; and thus we have a means of ascertaining ancient dates if we have any record of the position of the pole among the stars at the epochs in question. The Secret Doctrine speaks often in veiled terms of movements of the earth's axis and hence of the position of the celestial north pole. Of the first continent, the Sacred Imperishable Land, it is said that the pole star has his watchful eye upon it from the dawn to the close of the twilight of a day of the Great Breath. Again, at one time a star in the constellation Draco occupied the position.
In India the pole star is known as Dhruva, and the celestial or cosmic north pole, as well as the terrestrial north pole, is called Meru, the seat of Brahma.

pole-star /'poulstɑ:/
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