What is a circumpolar star?

Circumpolar stars are visible every night of the year from certain latitudes because their paths around the celestial pole never dip below the horizon. Which stars are circumpolar depends on where you are on Earth: the farther you are from the equator, the larger the circumpolar region becomes. In the Northern Hemisphere, Polaris is the best-known example, while in the Southern Hemisphere there is no bright pole star as prominent as Polaris. These stars are useful for navigation and for understanding Earth’s rotation and the night sky.