111P/Helin–Roman–Crockett
| Discovery[1] | |
|---|---|
| Discovered by | |
| Discovery site | Palomar Observatory (675) |
| Discovery date | 5 January 1989 |
| Designations | |
| P/1989 A2 | |
| 1988 XIII, 1989b[2] | |
| Orbital characteristics[4][5] | |
| Epoch | 25 February 2023 (JD 2460000.5) |
| Observation arc | 23.97 years |
| Earliest precovery date | 2 January 1989 |
| Number of observations | 152 |
| Aphelion | 4.595 AU |
| Perihelion | 3.707 AU |
| Semi-major axis | 4.151 AU |
| Eccentricity | 0.1402 |
| Orbital period | 8.457 years |
| Inclination | 4.226° |
| 89.827° | |
| Argument of periapsis | 1.109° |
| Mean anomaly | 72.094° |
| Last perihelion | 16 June 2021 |
| Next perihelion | 9 December 2029[3] |
| TJupiter | 3.023 |
| Earth MOID | 2.721 AU |
| Jupiter MOID | 0.589 AU |
| Physical characteristics | |
Mean radius | 0.6 km (0.37 mi)[6] |
| Comet total magnitude (M1) | 8.4 |
| Comet nuclear magnitude (M2) | 17.2 |
111P/Helin–Roman–Crockett is an Encke-type comet with an 8.46-year orbit around the Sun. It was co-discovered by Eleanor and Ron Helin, Brian P. Roman and Randy L. Crockett on 5 January 1989 from images obtained about 1-2 days prior.
Orbit
[edit]Comet Helin–Roman–Crockett is known for making extremely close approaches to Jupiter being a quasi-Hilda comet.[7] During these approaches, it actually orbits Jupiter.[8] The last such approach was in 1976,[4] the next will be in 2071.[4] The Jovian orbits are highly elliptical and subject to intense Solar perturbation at apojove which eventually pulls the comet out of Jovian orbit for the cycle to begin anew.
Simulations predict such a cycle is unstable, the object will either be captured into an encounter orbit (e.g. Shoemaker-Levy 9) or expelled into a new orbit which does not have periodic approaches. This implies that 111P's orbit is recent within the past few thousand years.
Physical characteristics
[edit]Estimates for the size of its nucleus in 2004 place it roughly about 1.2 km (0.75 mi) in diameter.[6] Follow-up studies in 2007 generally agree with this estimate, and depending on the comet's activity involved, the comet is likely somewhere between 0.92–2.78 km (0.57–1.73 mi) in diameter.[9]
References
[edit]- ^ E. F. Helin; R. Helin; B. P. Roman; R. L. Crockett (5 January 1989). B. G. Marsden (ed.). "Comet Helin–Roman–Crockett (1989b)". IAU Circular. 4701 (1). Bibcode:1989IAUC.4701....1H.
- ^ "Comet Names and Designations". International Comet Quarterly. Retrieved 20 October 2025.
- ^ "Horizons Batch for 111P/Helin-Roman-Crockett on 2029-Dec-09" (Perihelion occurs when rdot flips from negative to positive). JPL Horizons. Retrieved 12 September 2021. (JPL#8/Soln.date: 2013-Jan-28)
- ^ a b c "111P/Helin–Roman–Crockett – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory. Retrieved 26 July 2012.
- ^ "111P/Helin–Roman–Crockett Orbit". Minor Planet Center. Retrieved 17 June 2014.
- ^ a b P. L. Lamy; I. Toth; Y. R. Fernández; H. A. Weaver (2004). "The Sizes, Shapes, Albedos, and Colors of Cometary Nuclei" (PDF). Comets II. University of Arizona Press. pp. 223–264. Bibcode:2004come.book..223L. doi:10.2307/j.ctv1v7zdq5.22. ISBN 978-0-8165-2450-1. JSTOR j.ctv1v7zdq5.22.
- ^ G. Tancredi; M. Lindgren; H. Ricjman (1990). "Temporary satellite capture and orbital evolution of Comet P/Helin–Roman–Crockett". Astronomy & Astrophysics. 139 (1/2): 375–380. Bibcode:1990A&A...239..375T. ISSN 0004-6361.
- ^ G. Tancredi (1990). "The capture of P/Helin–Roman–Crockett by Jupiter". Comptes-rendus de la table ronde: Nouveaux Développements en Planétologie Dynamique (in French). pp. 273–279. Bibcode:1990ndpd.conf..273T.
- ^ E. M. Epifani; P. Palumbo; M. T. Capria; et al. (2007). "The distant activity of Short Period Comets*– I". Monthly Notices of the Royal Astronomical Society. 381 (2): 713–722. Bibcode:2007MNRAS.381..713M. doi:10.1111/j.1365-2966.2007.12181.x.
External links
[edit]- 111P/Helin–Roman–Crockett at the JPL Small-Body Database
- 111P/Helin–Roman–Crockett at Seiichi Yoshida's website
- 111P/Helin–Roman–Crockett at Gary W. Kronk's Cometography
- Helin, E.; Helin, R.; Roman, B.; Crockett, R.; Seki, T.; Kobayashi, T.; Endate, K.; Watanabe, K.; Shao, C. -Y.; Levy, D. (1989). "Comet Helin-Roman-Crockett (1989b)". International Astronomical Union Circular (4714): 1. Bibcode:1989IAUC.4714....1H.
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