Calculations by other methods vary widely.Īlthough appearing to the naked eye as a single point of light, Polaris is a triple star system, composed of the primary, a yellow supergiant designated Polaris Aa, in orbit with a smaller companion, Polaris Ab the pair is in a wider orbit with Polaris B. The revised Hipparcos stellar parallax gives a distance to Polaris of about 433 light-years (133 parsecs), while the successor mission Gaia gives a distance of about 448 light-years (137 parsecs). The stable position of the star in the Northern Sky makes it useful for navigation.Īs the closest Cepheid variable its distance is used as part of the cosmic distance ladder.
The position of the star lies less than 1° away from the north celestial pole, making it the current northern pole star. With an apparent magnitude that fluctuates around 1.98, it is the brightest star in the constellation and is readily visible to the naked eye at night. It is designated α Ursae Minoris ( Latinized to Alpha Ursae Minoris) and is commonly called the North Star or Pole Star. Polaris is a star in the northern circumpolar constellation of Ursa Minor. Polaris, North Star, Cynosura, Alpha UMi, α UMi, ADS 1477, CCDM J02319+8915
