Celestial body is only a general name for an object in the sky, particlarly applied to the night sky (but including the Sun). The moon, stars, planets, etc., are considered celestial bodies.
Most of them were identified by the ancients; in modern times the more distant planets from Earth were discovered by use of more powerful telescopes.
The north and south celestial poles are two imaginary points and therefore cannot be "discovered".
That depends on how you define "celestial body". Arguably, the largest "celestial body" thus far discovered (or ever likely to be discovered) is the universe itself. However, let's assume you mean a compact body, i.e. one which is more or less continuous (and thus excludes things like galaxies, globular clusters, and nebulae). The largest star known is VY Canis Majoris, which is roughly the size of the orbit of Saturn. The largest body in the Solar system is, of course, the Sun. Jupiter is second, at about 0.1% the volume of the Sun.
A celestial body is any physical body beyond the earth's atmosphere.
No sun doesn't revolve to any celestial body, but the celestial body revolve around the sun.
The Space Station is no a celestial body. Celestial bodies are natural -- not man made.
The moonMoon is the closet celestial body.
satellite
Who ever discovers it.
No, a supernova is an explosion of a star. What left of a supernova are celestial bodies.
A Comet
A large celestial body that is composed of gas and emits light is called a star.
Saturn.