Once the brightest star in the constellation, it now has a magnitude of only 3.6. 4,800 years ago, during the time of ancient Egypt, it marked the northern celestial pole and was only 10 arc minutes away from it. However, due to the precession of the Earth's axis, the pole has since shifted towards Polaris, and Thuban is now over 25 degrees away from it. Thuban belongs to the spectral class AO and is located between Mizara and Kochab. It is 215 light-years away and is 135 times brighter than the Sun.