No matter where you are on Earth, stars appear to rotate about a point called the celestial pole. This point corresponds to the extension of Earth's axis of rotation onto the celestial sphere. In the northern hemisphere, this is called the North Celestial Pole (NCP) , near which the star Polaris (the Pole Star) is located. In the southern hemisphere, the analogous point is the South Celestial Pole (SCP)
- At the North Pole, the North Celestial Pole is directly overhead (at the zenith), and stars appear to move in horizontal, circular paths around it.
- At the equator, the celestial poles lie on the horizon, so stars appear to rise vertically from the east and set vertically in the west, rotating around points on the horizon.
- At intermediate latitudes, the celestial pole appears at an altitude equal to the observer's latitude above the horizon, and stars rotate in circular paths around that point, which is midway between the horizon and the zenith
Thus, the celestial poles serve as the fixed points around which the entire star field appears to rotate due to Earth's rotation on its axis
