82P/Gehrels
{{Short description|Periodic comet}}
{{use dmy dates|date=April 2025}}
{{Infobox comet
| name = 82P/Gehrels
| image =
| discovery_ref = {{r|IAUC_2861}}
| discoverer = Tom Gehrels
| discovery_site = Palomar Observatory
| discovery_date = 27 October 1975
| mpc_name = P/1975 U1
P/1984 P1
| designations = {{unbulleted|Gehrels 3|1977 VII, 1985 IV, 1993 XIV|1975o, 1984l, 1992v}}
| orbit_ref = {{r|jpldata|mpc}}
| epoch = 25 February 2023 (JD 2460000.5)
| observation_arc = 44.56 years
| obs = 149
| perihelion = 3.629 AU
| aphelion = 4.638 AU
| semimajor = 4.133 AU
| period = 8.403 years
| eccentricity = 0.12207
| inclination = 1.1259°
| asc_node = 239.25°
| arg_peri = 226.43°
| mean = 200.37°
| tjup = 3.027
| Earth_moid = 2.643 AU
| Jupiter_moid = 0.517 AU
| physical_ref = {{r|Lamy_2004}}
| dimensions = {{cvt|1.46|km|mi}}
| M1 = 7.6
| M2 = 16.4
| last_p = 28 June 2018{{r|Yoshida-82p|Rocher_2011}}
| next_p = 14 November 2026{{r|Horizons2026}}
}}
82P/Gehrels is a periodic comet that was discovered on 27 October 1975, by Tom Gehrels at the Palomar Mountain Observatory in California having a faint nuclear brightness of magnitude 17.{{r|jpldata}}
Calculations based on the early sightings gave an estimated perihelion of 23 April 1975 and an orbital period of 8.11 years. It was observed by J. Gibson on its next predicted apparition in 1984, using the 122-cm Schmidt at Palomar, when he estimated the nuclear brightness at a very faint magnitude 20. It has since been observed in 1993, 2001 and 2010.{{r|cometography}}
The object has been identified as a quasi-Hilda comet, which means it is near a 3:2 mean-motion resonance with the planet Jupiter.{{r|Ohtsuka_2008}} It fits the definition of an Encke-type comet with (TJupiter > 3; a < aJupiter).{{r|jpldata}} It has an estimated diameter of {{cvt|1.46|km|mi}}.{{r|Lamy_2004}}
On 15 August 1970 the comet passed {{cvt|0.00143|AU|km mi}} from Jupiter.{{r|jpldata}}
See also
References
{{reflist|refs=
| author1= G. W. Kronk
| title= 82P/Gehrels 3
| url= https://cometography.com/pcomets/082p.html
| website= Cometography.com
| access-date= 24 February 2015 }}
| title= Horizons Batch for 82P/Gehrels 3 (90000860) on 2026-Nov-14
| publisher= JPL Horizons
| type= Perihelion occurs when rdot flips from negative to positive
| url= https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D82P%3BCAP%27&START_TIME=%272026-Nov-12%27&STOP_TIME=%272026-Nov-17%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27
| access-date= 27 June 2022 }} (JPL#19 Soln.date: 2021-Mar-19)
| author1= T. Gehrels
| editor1= B. G. Marsden
| title= Possible Comet Gehrels
| url= http://www.cbat.eps.harvard.edu/iauc/02800/02861.html
| journal= IAU Circular
| volume= 2861
| pages= 1
| year= 1975
| bibcode= 1975IAUC.2861....1S }}
| title= 82P/Gehrels 3 – JPL Small-Body Database Lookup
| url= https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=82P
| website= ssd.jpl.nasa.gov
| publisher= Jet Propulsion Laboratory
| access-date= 18 February 2012 }}
| author1= P. L. Lamy
| author2= I. Toth
| author3= Y. R. Fernandez
| author4= H. A. Weaver
| editor1= M. C. Festou
| editor2= H. U. Keller
| editor3= H. A. Weaver
| title= Comets II
| chapter= The sizes, shapes, albedos, and colors of cometary nuclei
| year= 2004
| bibcode= 2004come.book..223L }}
| title= 82P/Gehrels Orbit
| url= http://www.minorplanetcenter.net/db_search/show_object?object_id=82P
| publisher= Minor Planet Center
| access-date= 29 March 2025 }}
| author1= K. Ohtsuka
| author2= T. Ito
| author3= M. Yoshikawa
| author4= D. J. Asher
| author5= H. Arakida
| title= Quasi-Hilda comet 147P/Kushida-Muramatsu. Another long temporary satellite capture by Jupiter
| journal= Astronomy and Astrophysics
| year= 2008
| volume= 489
| issue= 3
| pages= 1355–1362
| bibcode= 2008A&A...489.1355O
| arxiv= 0808.2277
| s2cid= 14201751
| doi= 10.1051/0004-6361:200810321 }}
| author1= P. Rocher
| title= Note number: 0090 P/Gehrels 3 : 82P
| url= http://www.imcce.fr/en/ephemerides/donnees/comets/FICH/CIF0090.php
| publisher= IMCCE
| date= 23 March 2011
| access-date= 19 February 2012 }}
| author1= S. Yoshida
| title= 82P/Gehrels 3
|url=http://www.aerith.net/comet/catalog/0082P/index.html
| website= www.aerith.net
| date= 3 July 2011
| access-date= 18 February 2012 }}
}}
External links
- {{JPL Small Body|id=1000031}}
{{PeriodicComets Navigator|81P/Wild|83D/Russell}}
{{Comets}}
{{Authority control}}
{{DEFAULTSORT:Gehrels, 082P}}