- The Pole Star, also known as the Polaris and the North Star, is located at True North and is stationary throughout the Year.
- The Pole Star is at 90° to the Celestial Equator, the Ecliptic.
Stella Maris
- Its name in Latin was ‘Stella Maris’ (Sea Star) because of its importance to sailors in Celestial Navigation.
Finding the Pole Star
- The Pole Star is the brightest star in the Ursa Minor constellation.
- An axis line from the south pole to the north pole passes straight through the pole star to within one degree.
- Therefore the Pole Star appears never to move.
- In the Northern Hemisphere, the celestial sphere containing all the stars and planets appears to revolve anticlockwise around the pole star.
Celestial Navigation
- Polaris was known as ‘Stella Maris’ because of its importance to sailors:
- True North:
- The Pole star is positioned within one degree of True North and is stationary, therefore it is easy to use for orientation in Celestial Navigation.
- Latitude:
- Because the Pole Star can be seen in the night sky in the Northern Hemisphere at all times, it can be used to calculate Latitude.
- If the angle between the observer and the Pole Star is 51 degrees above the Horizon, then the observer is at Latitude 51 degrees North.