Polaris

Polaris (also known as the pole star or the North Star) was a star visible from Earth in the constellation of Ursa Minor. Ian Chesterton once was showed it to Vicki Pallister in 64 (PROSE: Byzantium!, TV: Legend of the Sea Devils) and again to Barbara Wright shortly after leaving that year. (PROSE: The Eleventh Tiger)

In 1699, Captain Henry Avery explained to the Eleventh Doctor that he used the North Star to navigate his ship. (TV: The Curse of the Black Spot)