Explanation:
In the northern hemisphere the star [tex]\alpha Ursae Minoris[/tex] , located in the constellation of the Little Bear (Ursa Minor in latin) is the polar star (known as Polaris).
This is because this star is currently located very close to the Earth rotation axis. That is why when observing the sky in the north direction, being in the northern hemisphere, Polaris will seem immobile in the middle of the rest of the stars.
However, it is necessary to note that [tex]\alpha Ursae Minoris[/tex] will not always be the polar star, because each year the Earth's totation axis moves approximately one degree, which will cause another star ([tex]\gamma Cephei[/tex] ) to take the place of Polaris within many years.
