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 star to the north celestial pole and remains nearly stationary throughout the night
ModL < ML (stella) polaris, polar (star): see pole
See Polaris in American Heritage Dictionary 4
A star of the second magnitude, at the end of the handle of the Little Dipper and almost at the north celestial pole. Also called North Star, polar star, polestar.