Celestial point a re two imagineryline sor pont on the sky, where the earths rotational axis is bisected by the plane.
Explanation:
North and south poles are located directly over this and are fixed. The NCP is found within one degree of the brightness star i.e Polaris as the "North Star". This Polaris is located close to NCP for a small 25,700-year precession cycle.
The true North Star", though it will be about six degrees from the true north celestial pole. This can be found throughout the doppler effect.
Zenith is an imaginary line directly above the imaginary celestial spheres and is opposite to the gravitational force towards the nadir. This term is related to the earth like rocky planet an not the star-like the sun as it does not have its zenith.
