A periodic comet discovered in 1788 by C. L. Herschel. A comet discovered in 1939 by the French astronomer Roger Rigollet (1909–81) turned out to be a return of the same object. It was at that time the periodic comet with the longest period, currently 155 years, to have been seen more than once, although it has now been superseded by Comet Ikeya–Zhang. Its perihelion is 0.748 AU, eccentricity 0.974, and inclination 64°.2.
http://cometography.com/pcomets/035p.html Information page at Cometography website.
Subjects: Astronomy and Astrophysics.