25D/Neujmin

25D/Neujmin, otherwise known as Comet Neujmin 2, is a periodic comet in the Solar System discovered by Grigory N. Neujmin (Simeis) on February 24, 1916.^[2] It was last observed on February 10, 1927.^[3]

25D/Neujmin

Discovery
Discovered by	Grigory Neujmin
Discovery date	24 February 1916
Orbital characteristics
Epoch	31 December 1926
Aphelion	4.84 AU
Perihelion	1.338 AU
Semi-major axis	3.089 AU
Eccentricity	0.567
Orbital period	5.43 yr
Inclination	10.638°
Last perihelion	18 August 2019[1] (unobserved)
Next perihelion	11 May 2025[1] (Lost since 1927)

It was confirmed by George Van Biesbroeck (Yerkes Observatory, Wisconsin, United States) and Frank Watson Dyson (Greenwich Observatory, England) on March 1.^[2]

A prediction by Andrew Crommelin (Royal Observatory, Greenwich, England) for 1921 was considered unfavourable and no observations were made. The comet was recovered in 1926.^[3] Searches in 1932 and 1937 were unsuccessful.^[2]

Consequently, this comet has remained a lost comet since 1927. As of 2019^[update] and using the JPL Horizons nominal orbit, the comet is still expected to come to perihelion around 1.3 AU from the Sun.