|Discovered by||Grigory Neujmin|
|Discovery date||24 February 1916|
|Orbital characteristics A|
|Epoch||31 December 1926|
|Semi-major axis||3.089 AU|
|Orbital period||5.43 yr|
|Last perihelion||18 August 2019?|
12 March 2014?
|Next perihelion||11 May 2025?|
(Lost since 1927)
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. It was last observed on February 10, 1927.
It was confirmed by George Van Biesbroeck (Yerkes Observatory, Wisconsin, United States) and Frank Watson Dyson (Greenwich Observatory, England) on March 1.
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. Searches in 1932 and 1937 were unsuccessful.
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.