circumpolar star

Any star that appears to circle around the Earth's North and/or South Pole without either rising or setting, as a result of the motion of the Earth. The radius of the area around the North Pole in which such stars occur is equal to the latitude of the place of observation. Thus at the pole all visible stars are circumpolar, while at the Equator none are. From London, England, for example, all stars within 52° of the North Pole are circumpolar.