External links
- 331P in SDSS (26 August 2004)
- 331P confirmation observations, Malina River Observatory (23 March 2012) Archived 5 December 2021 at the Wayback Machine
| Discovery | |
|---|---|
| Discovered by | A. R. Gibbs (Mount Lemmon Survey) |
| Discovery date | March 22, 2012 |
| Orbital characteristics | |
| Epoch | 4 February 2012 (JD 2455961.5) |
| Observation arc | 11.3 years |
| Number of observations | 148 |
| Aphelion | 3.130 AU |
| Perihelion | 2.877 AU |
| Semi-major axis | 3.004 AU |
| Eccentricity | 0.042 |
| Orbital period | 5.21 years (1902 days) |
| Inclination | 9.740° |
| 216.86° | |
| Argument of periapsis | 177.40° |
| Last perihelion | 29 September 2020 [1] 16 June 2015 |
| Next perihelion | 2025-Dec-25 [1] |
| TJupiter | 3.229 |
| Earth MOID | 1.88 AU |
| Jupiter MOID | 2.08 AU |
| Physical characteristics [2] | |
Mean diameter | 1.77 km (1.10 mi) |
| 3.24±0.01 hours | |
| Comet total magnitude (M1) | 12.3 |
| Comet nuclear magnitude (M2) | 15.4 |
331P/Gibbs (P/2012 F5) is a small periodic Encke-type and rare main-belt comet, discovered by American amateur astronomer Alex Gibbs. [3]
It is a rare type of comet called a main-belt comet. Although most comets come from the Oort cloud or the Kuiper belt, main-belt comets are instead members of the asteroid belt that have a coma and tail. As of 2016, it is one of only 15 known main-belt comets. [4]
Precovery observations of 331P/Gibbs in Sloan Digital Sky Survey data were found dating to August 2004, in which the object was visible as a regular asteroid. Further observations in 2014 by the Keck Observatory showed that the comet was fractured into 5 pieces and rotating rapidly, with a rotation period of only 3.2 hours. Due to the YORP effect, P/2012 F5 had begun to spin so quickly that, being a likely rubble pile, parts began to be thrown off, leaving a very long dust trail. [5] This is very similar to 311P/PANSTARRS, being the best-established cause for main-belt comets along with impacts between small asteroids (such as with 596 Scheila and 354P/LINEAR).
