Caption: The celestial sphere and some of its salient features.

Features:

1. The displayed axis is the celestial axis which is just an extension of the Earth's axis to the celestial sphere itself.

2. The intersections of the celestial axis with the celestial sphere are the north celestial pole (NCP) (in the north) and the south celestial pole (SCP) (in the south wouldn't you know it).

3. Taking the Earth as the frame of rest, the celestial sphere rotates westward once per day on the celestial axis.

   To be exact, one sidereal day = 86164.0905 s = 1 day - 4 m + 4.0905 s (on average) which is the time between transits of the meridian of a fixed star.

4. The projection of the Earth's equator onto the celestial sphere is the celestial equator.

   The celestial sphere is a great circle---which is a circle that divides sphere in half.

5. The fixed stars rotate once per sidereal day on small circles---which are circles which divide a sphere unequally.

   Well fixed stars on the celestial equator rotate on a great circle, the celestial sphere itself.

6. The constellations and asterism (non-IAU constellations) also rotate once per sidereal day, of course.

7. Little Dipper is one such asterism.

8. Polaris, the end of the handle of the Little Dipper, is the pole star of our historical period.

   It is 44'9.2'' ≅ 0.75° from the NCP (for epoch J2000).

   This means that Polaris executes only a tiny small circle around the NCP and to casual observation in naked-eye astronomy does NOT seem to move at all.

9. To casual observation, Polaris defines the NCP.