25D/Neujmin
| Discovery | |
|---|---|
| Discovered by | Grigory Neujmin |
| Discovery date | 24 February 1916 |
| Designations | |
| D/1916 D1 D/1926 V2 | |
| |
| Orbital characteristics[5] | |
| Epoch | 21 March 1927 (JD 2424960.5) |
| Observation arc | 10.94 years[1] (Not observed in 99 years) |
| Number of observations | 116[1] |
| Aphelion | 4.840 AU |
| Perihelion | 1.338 AU |
| Semi-major axis | 3.089 AU |
| Eccentricity | 0.56682 |
| Orbital period | 5.429 years |
| Inclination | 10.639° |
| 328.72° | |
| Argument of periapsis | 193.70° |
| Mean anomaly | 11.577° |
| Last perihelion | 11 May 2025?[2] (unobserved) |
| Next perihelion | 24 Feb 2031?[3][4][2] (Lost since 1927) |
| TJupiter | 2.932 |
| Earth MOID | 0.35 AU |
| Comet total magnitude (M1) | 12.5 |
| Comet nuclear magnitude (M2) | 16.0 |
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.[6] 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.[6]
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.[6]
Consequently, this comet has remained a lost comet since 1927. As of 2026[update] and using the JPL Horizons nominal orbit, the comet is still expected to come to perihelion around 1.45 AU (217 million km) 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
[edit]- ^ a b c d "25D/Neujmin Orbit". Minor Planet Center. Retrieved 26 February 2019.
- ^ a b c S. Yoshida. "25D/Neujmin 2". www.aerith.net. Retrieved 26 February 2019.
- ^ a b "Horizons Batch for 25D/Neujmin 2 (90000357) on 2031-Feb-24" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 5 April 2026. (JPL#7/Soln.date: 2003-Apr-18)
- ^ K. Kinoshita (31 May 2003). "25D/Neujmin past, present and future orbital elements". Comet Orbit. Retrieved 10 April 2026.
- ^ "25D/Neujmin 2 – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 25 November 2025.
- ^ a b c G. W. Kronk. "25D/Neujmin 2". Cometography.com. Retrieved 26 February 2018.
External links
[edit]- 25D/Neujmin at the JPL Small-Body Database
- 25D/Neujmin at Gary W. Kronk's Cometography
- 25D/Neujmin at Kazuo Kinoshita's website
- 25D/Neujmin at Seiichi Yoshida's website
