The Movement of the Sky as seen from the North Pole
This animation shows the movement of the sky as seen from the North Pole during the course of one rotation of the Earth, i.e. one sidereal day. The animation shows the whole sky. The thick black line is the horizon. The actual sky is a hemisphere and so there is some distortion as this is projected on the 2D animation. The clock in the lower left-hand corner shows the Local Sidereal Time. Over the course of one day the celestial sphere rotates once around the observer with no objects rising or setting.
The grey lines are the RA-Dec grid of the celestial sphere; RA lines are shown every 3 hours ( 0, 3, 6, 9, 12, 15, 18, 21 ), Dec lines are shown every 30° ( +30°, +60°). The celestial equator lies around the horizon. The green line is the ecliptic ( = the apparent annual path of the Sun on the celestial sphere). The ecliptic plane is tilted 23.5° with respect to the plane of the celestial equator since the Earth’s spin axis is tilted 23.5°. The pole star (Polaris) can be seen at Dec = 90°. The animation starts at a Local Sidereal Time (LST) of 0 hours.