108P/Ciffréo
Jupiter-family comet
From Wikipedia, the free encyclopedia
108P/Ciffréo is a Jupiter-family comet with an orbital period of 7.25 years around the Sun. It is the only comet discovered by French astronomer, Jacqueline Ciffréo.[6] The comet is noted for having a peculiar double morphology, in which the nucleus is accompanied by a comoving, detached, diffuse tail, which is probably a perspective artifact of particles ejected sunwards and then repelled by solar wind.[1][7]
Comet Ciffréo imaged by the Hubble Space Telescope from 31 January to 24 May 2022.[1] | |
| Discovery[2] | |
|---|---|
| Discovered by | Jacqueline Ciffréo |
| Discovery site | Caussols, France |
| Discovery date | 8 November 1985 |
| Designations | |
| P/1985 V1, P/1992 S1 | |
| |
| Orbital characteristics[3][4] | |
| Epoch | 21 November 2025 (JD 2461000.5) |
| Observation arc | 36.38 years |
| Number of observations | 2,612 |
| Aphelion | 5.824 AU |
| Perihelion | 1.664 AU |
| Semi-major axis | 3.744 AU |
| Eccentricity | 0.581 |
| Orbital period | 7.245 years |
| Inclination | 11.432° |
| 50.274° | |
| Argument of periapsis | 354.56° |
| Mean anomaly | 208.49° |
| Last perihelion | 11 October 2021 |
| Next perihelion | 9 December 2028[5] |
| TJupiter | 2.750 |
| Earth MOID | 0.535 AU |
| Jupiter MOID | 0.283 AU |
| Physical characteristics[3] | |
Mean diameter | 0.5 km (0.31 mi)[1] |
| Comet total magnitude (M1) | 10.9 |
| Comet nuclear magnitude (M2) | 15.9 |
Observational history
The comet was discovered by Jacqueline Ciffréo on 8 November 1985 using a 0.9 m Schmidt camera at Caussols. The comet was then a diffuse object with an apparent magnitude of 10. H. Kosai from the Tokyo Observatory noticed on 9 November that it also had a faint tail about 1.5 arcminutes long.[2] An elliptical orbit was published by Daniel W. E. Green on 18 November, with an estimated orbital period of 7.81 years, while perihelion had taken place on 28 October 1985 at a distance of 1.72 AU (257 million km).[8] Further observations revealed that the perihelion was on 30 October and the orbital period of the comet was 7.22 years.[6] In December 1985, a detacted coma or tail was detected 6 arcseconds from the nucleus of the comet and extending for 20 arcseconds to the north-east.[9] The visual magnitude of the comet was estimated to be 12.5.[10]
The comet was recovered on 24 September 1992 by J. V. Scotti with the Spacewatch telescope.[11] The comet passed perihelion on 23 January 1993. The next perihelion was in April 2000 and the comet was observed in November and December 1999 and November and December 2000.[6] During the 2014 and 2021 apparition the comet featured a detached coma, similar to that observed in 1985.[7] The peculiar morphology was attributed to a possible fragmentation event,[12] but further observations revealed it is most probably an artifact of the turnaround of particles ejected sunward and repelled by sunlight.[1]
Orbit
The comet is at a 5:3 orbital resonance with Jupiter, allowing for frequent planetary encounters.[13] Between 1900 and 2183, its closest approach to Jupiter will occur on 18 December 2076 at a distance of 0.28 AU (42 million km).[3]
Initial orbital calculations of the comet indicated that it was a recently captured object. However, follow-up studies in 1990 later revealed that its dynamical behavior corresponds to a relatively "aged" object instead, where it has been on its current orbit for at least 1,500 revolutions since at least 12,000 BC.[14]