Before giving a permanent number to a periodic comet, the comet needs to pass through the perihelion again after being found, or get the proof that it has passed before it can be numbered.For example, Comet Ikeya Chang, with the number "153P", has a revolution period of more than 360 years. It was proved that it was the same comet as the comet that appeared in 1661, so it was numbered.
Comets are usually named after their discoverers, but a few are named after their orbital calculators, such as those coded as "2P"Comet EnkeAnd "27P"Comet Cromalin。At the same time, the orbit and revolution period of comets will be changed due to the influence of Jupiter and other large celestial bodies. They also disappear for some reason and can no longer be found, including disintegration in the air, planetary gravity, and depletion of matter through the comet tail.
