Periodic comets can only be seen from earth once every few years or decades.

Periodic comets also have a number indicating the order of their discovery.

Two of them were named after Brorsen as they are periodic comets.

D/ indicates a periodic comet that has disappeared, broken up, or been lost.

A periodic comet is a comet which orbits around the Sun.

He observed the bright comet of the 1860 and two years later discovered a periodic comet.

He discovered a number of comets, including the lost periodic comet 34D/Gale.

A number of periodic comets discovered in earlier decades or previous centuries are now lost comets.

His former mathematics professor published this note and Encke became famous as the discoverer of the short periodic comets.

Eventually, perturbations from the giant planets send such objects towards the Sun, transforming them into periodic comets.

Notably, he successfully predicted the 1992 return of the once-lost periodic comet Swift-Tuttle.

Comet Brorsen-Metcalf is a periodic comet with an orbital period of 70 years.

The Kuiper belt was initially thought to be the main repository for periodic comets, those with orbits lasting less than 200 years.

There is however another comet population, known as short-period or periodic comets; those, like Halley, with orbits lasting less than 200 years.

He also suggested in 1978 that the Tunguska event was a fragment of the periodic comet Encke.

The parent body of the shower is Halley's Comet, a periodic comet.

Periodic comets visit again and again.

He also discovered the periodic comet 196P/Tichý.

He co-discovered the lost periodic comet 18D/Perrine-Mrkos and several other comets.

- Periodic Comets.

She is also a co-discoverer of periodic comet 127P/Holt-Olmstead.

Wiseman discovered periodic comet 114P/Wiseman-Skiff while working as an undergraduate research assistant in 1987.

Either of these numbered periodic comets:

He discovered twelve comets between 1940 and 1968, including the periodic comet 45P/Honda-Mrkos-Pajdušáková.

However, the periodic comet 61P/Shajn-Schaldach was co-discovered by his wife rather than by him.