| Discoverer | Grigory Neujmin |
|---|---|
| Discovery date | 24 February 1916 |
| Mpc name | D/1916 D1 D/1926 V2 |
| Designations |
|
| Epoch | 21 March 1927 (JD 2424960.5) |
| Observation arc | 10.94 years[1] (Not observed in 99 years) |
| Obs | 116[1] |
| Perihelion | 1.338 AU |
| Aphelion | 4.840 AU |
| Semimajor | 3.089 AU |
| Eccentricity | 0.56682 |
| Period | 5.429 years |
| Inclination | 10.639° |
| Asc node | 328.72° |
| Arg peri | 193.70° |
| Mean | 11.577° |
| Tjup | 2.932 |
| Earth moid | 0.35 AU |
| M 1 | 12.5 |
| M 2 | 16.0 |
| Last p | 11 May 2025?[2] (unobserved) |
| Next p | 24 Feb 2031?[3][4][2] (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.[5] It was last observed on February 10, 1927, and has not been observed in 99 years.[1]
It was confirmed by George Van Biesbroeck (Yerkes Observatory, Wisconsin, United States) and Frank Watson Dyson (Greenwich Observatory, England) on March 1.[5]
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.[1] Searches in 1932 and 1937 were unsuccessful.[5]
Consequently, this comet has remained a lost comet since 1927. As of 2026 and using the JPL Horizons nominal orbit, the comet is still expected to come to perihelion around 1.45 astronomical units from the Sun.[3]
The comet has not been observed during the last 18 perihelion passages: 1932, 1937, 1943, 1948, 1954, 1959, 1965, 1971, 1976, 1981, 1987, 1992, 1998, 2003, 2008, 2014, 2019, and 2025.[2]
References
- ^ "25D/Neujmin Orbit". Minor Planet Center. Retrieved 2019-02-26.
- ^ S. Yoshida. "25D/Neujmin 2". www.aerith.net. Retrieved 2019-02-26.
- ^ "Horizons Batch for 25D/Neujmin 2 (90000357) on 2031-Feb-24" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 2026-04-05. (JPL#7/Soln.date: 2003-Apr-18)
- ^ K. Kinoshita (2003-05-31). "25D/Neujmin past, present and future orbital elements". Comet Orbit. Retrieved 2026-04-10.
- ^ G. W. Kronk. "25D/Neujmin 2". Cometography.com. Retrieved 2018-02-26.
External links
- 25D/Neujmin at Gary W. Kronk's Cometography
- 25D/Neujmin at Kazuo Kinoshita's website
- 25D/Neujmin at Seiichi Yoshida's website