A quasi-Hilda comet (QHC) is a
Jupiter-family comet that interacts strongly with
Jupiter and undergoes extended temporary capture by it. These comets are associated with the
Hilda asteroid
The Hilda asteroids (adj. ''Hildian'') are a dynamical group of more than 5,000 asteroids located beyond the asteroid belt but within Jupiter's orbit, in a 3:2 orbital resonance with Jupiter. The namesake is the asteroid 153 Hilda.
Hildas move i ...
zone in the 3:2 inner
mean-motion resonance with Jupiter. Typically, asteroids in this zone have a
semimajor axis between 3.70 and 4.20
AU,
eccentricities below 0.30, and
inclinations of no more than 20°.
[ Comets can be temporarily perturbed into this group and then perturbed back out again.][ Eight percent of the comets that leave the 3:2 resonance end up impacting Jupiter.][
]
Known quasi-Hilda comets
These numbered comets belong to the group of quasi-Hilda comet:[
]39P/Oterma
39P/Oterma is a currently inactive List of periodic comets, periodic comet with an orbital period of nearly 20 years that stays outside the orbit of Jupiter. The comet nucleus, nucleus has a diameter around 4–5 km. It was last observed in Augu ...
was a quasi-Hilda before a close approach to Jupiter in 1963.[ ]77P/Longmore
77P/Longmore is a periodic comet in the Solar System, with a period of 6.8 years.
It was discovered by Andrew Jonathan Longmore on a photographic plate taken on 10 June 1975 at the 1.22m Schmidt telescope at Siding Spring Observatory, New Sout ...
falls outside of the bulk distribution because of its large eccentricity and inclination.[ Comet Shoemaker–Levy 9 impacted with Jupiter in 1994.
Not numbered comets claimed to be quasi-Hilda object with comet activity are P/2010 H2 (Vales), 2009 DQ118, 2018 CZ18 and 2004 CV50.]
References
{{reflist, refs=
[{{cite journal , title=The quasi-Hilda subgroup of ecliptic comets - an update , last=Toth , first=I. , journal=Astronomy and Astrophysics , volume=448 , issue=3 , pages=1191–1196 , date=March 2006 , doi=10.1051/0004-6361:20053492 , bibcode=2006A&A...448.1191T , doi-access=free ]
[{{cite journal , title=The Hilda group of minor planets , last=Spratt , first=Christopher E. , journal=Journal of the Royal Astronomical Society of Canada , volume=83 , pages=393–404 , date=December 1989 , bibcode=1989JRASC..83..393S ]
Comets
Jupiter