Polaris (Alpha Ursae Minoris) is called the North Star because it is currently very close to the north celestial pole, the point in space where the spin axis of the Earth points in the northern hemisphere. This is the point where all of the northern celestial objects in the sky appear to rotate around because of the Earth's rotation on its axis. Polaris is a multiple star system consisting of Polaris A, the bright star we see with our unaided eyes, Polaris B, a 9th magnitude star that is visible in small telescopes 18 arcseconds away, and two other fainter more distant companions. Polaris shines at 2nd magnitude, and is also a Cepheid variable star that varies slightly in brightness over a 4-day period. It is a spectral-type F7 supergiant star with 2,500 times the mass of our Sun. It is located 430 light-years away from us.