Polestars

Polestars, also known as the Pole Star or the North Star, is a general term referring to stars that are close to the celestial pole. Currently, the star closest to the North Celestial Pole is Polaris, a star in the constellation Ursa Minor. Due to precession, the Earth's axis slowly wobbles over thousands of years, causing the celestial pole to shift. This means that the identity of the Polestar changes over long periods. For instance, around 3000 BC, Thuban in the constellation Draco was the North Star. In the future, approximately 12,000 years from now, Vega will be the Polestar.

Polaris is a yellow supergiant and is part of a multiple star system. Its apparent brightness makes it easily visible in the Northern Hemisphere sky. For centuries, Polaris has been an invaluable tool for navigation. Its fixed position in the sky means that its altitude above the horizon directly corresponds to the observer's latitude. Sailors and travelers have historically used Polaris to determine their direction and position.

The concept of a Polestar is not unique to Earth. Other celestial bodies with axial tilt and rotation also have stars that appear to be fixed in their sky, serving as navigational aids. However, the term "Polestar" most commonly refers to the North Star in Earth's sky.