65P/Gunn
Periodic comet
From Wikipedia, the free encyclopedia
65P/Gunn is a periodic comet in the Solar System orbiting the Sun every 6.41 years inside the main asteroid belt between the orbits of the planets Mars and Jupiter.[1]
| |
| Discovery[2] | |
|---|---|
| Discovered by | James E. Gunn |
| Discovery site | Palomar Observatory |
| Discovery date | 17 October 1970 |
| Designations | |
| P/1954 P1, P/1970 U2 | |
| |
| Orbital characteristics[3][4] | |
| Epoch | 17 October 2024 (JD 2460600.5) |
| Observation arc | 71.13 years |
| Earliest precovery date | 8 August 1954[5] |
| Number of observations | 7,963 |
| Aphelion | 4.737 AU |
| Perihelion | 1.597 AU |
| Semi-major axis | 3.453 AU |
| Eccentricity | 0.3194 |
| Orbital period | 6.414 years |
| Inclination | 3.237° |
| 136.09° | |
| Argument of periapsis | 41.568° |
| Mean anomaly | 103.17° |
| Last perihelion | 16 June 2025 |
| Next perihelion | 11 February 2033[6] |
| TJupiter | 2.991 |
| Earth MOID | 1.903 AU |
| Jupiter MOID | 0.396 AU |
| Physical characteristics | |
Mean radius | < 5.4 km (3.4 mi)[7] |
| (V–R) = 0.54±0.06[8] | |
| Comet total magnitude (M1) | 10.1 |
Observational history
It was discovered on 11 October 1970 by James E. Gunn of Princeton University using the 122-cm Schmidt telescope at the Palomar Observatory.[2] It had a low brightness of magnitude 16 at that time.[9] In 1972, Elizabeth Roemer managed to observe 65P/Gunn close to aphelion.[10]
In 1980, it was noticed that a 19th magnitude comet found in plates obtained by Palomar Observatory on 8 August 1954 was a previous apparition of 65P/Gunn.[5] The link was confirmed by Toshiro Nomura and Brian G. Marsden.[11]
During the very favorable apparition of 1996, 65P/Gunn reached magnitude 12.[9]
Orbit
Physical characteristics
Infrared observations from the IRAS satellite in 1983 detected a dust trail around 65P/Gunn, indicating that it had a mass loss rate of 27±9 kg/s.[13] Additional observations from the Infrared Space Observatory in 1996 revealed a strongly asymmetric dust trail, with a higher mass loss rate of 100–300 kg/s by November 1996.[14]
CCD photometry conducted between 1993 and 1996 reveal a nucleus that is less than 11 km (6.8 mi) in diameter, later revised to 10.8 km (6.7 mi).[3][7] The comet was very active when it was observed, therefore the size estimate likely represent an upper limit.[7][8]