111P/Helin–Roman–Crockett

111P/Helin–Roman–Crockett is a periodic comet in the Solar System. It was discovered by Eleanor and Ron Helin on 5 January 1989 from images obtained on the 3rd and 4th of that month. It is a Jupiter family comet known for extremely close approaches to Jupiter being a Quasi-Hilda comet. During these approaches, it actually orbits Jupiter.[4] The last such approach was in 1976,[5] the next will be in 2071.[5] 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.

111P/Helin-Roman-Crockett

Discovery
Discovered by	Eleanor F. Helin Ron Helin Brian P. Roman Randy L. Crockett Palomar Observatory (675)
Discovery date	January 5, 1989
Alternative designations	1988 XIII
Orbital characteristics ^A
Epoch	March 6, 2006
Aphelion	4.607 AU
Perihelion	3.474 AU
Semi-major axis	4.041 AU
Eccentricity	0.1402
Orbital period	8.122 a
Inclination	4.2326°
Last perihelion	January 30, 2013[1] December 27, 2004[2]
Next perihelion	2021-Jun-15[3]

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. It fits the definition of an Encke-type comet with (T_Jupiter > 3; a < a_Jupiter).[6]

References

1. Syuichi Nakano (2005-10-26). "111P/Helin-Roman-Crockett (NK 1271)". OAA Computing and Minor Planet Sections. Retrieved 2012-02-24.
2. Seiichi Yoshida (2011-07-22). "111P/Helin-Roman-Crockett". Seiichi Yoshida's Comet Catalog. Retrieved 2012-02-24.
3. "111P/Helin-Roman-Crockett Orbit". Minor Planet Center. Retrieved 2014-06-17.
4. Tancredi, G. (1990). "The capture of P/Helin-Roman-Crockett by Jupiter". Comptes-rendus de la table ronde: nouveaux développements en planétologie dynamique. pp. 273–279. Bibcode:1990ndpd.conf..273T.
5. "JPL Close-Approach Data: 111P/Helin-Roman-Crockett" (2001-09-20 last obs). Retrieved 2012-02-24.
6. "JPL Small-Body Database Browser: 111P/Helin-Roman-Crockett" (2001-09-20 last obs). Jet Propulsion Laboratory. Retrieved 2012-07-26.

External links

• Orbital simulation from JPL (Java) / Horizons Ephemeris
• 111P/Helin-Roman-Crockett – Seiichi Yoshida @ aerith.net
• Elements and Ephemeris for 111P/Helin-Roman-Crockett – Minor Planet Center
• 111P at 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.
• Observations, www.oaa.gr.jp