The Pole or North Star
If you lie on your back looking at the night sky for a few hours, you will notice the sky rotating very slowly. In fact the sky will rotate once in a little less than twenty four hours so you will not be able to see a full rotation. During this rotation there will be a star in the night sky that appears to remain stationary. This star is called the Pole or North Star, and is on the axis of rotation of the Earth.
If you point a camera at the sky and leave the film exposed for a few hours, the rotation, and the position of the Pole Star is obvious.>/br>