 The comet on 12 November 2004, displaying a narrow tail | |
| Discovery[1] | |
|---|---|
| Discovered by | Siding Spring Observatory |
| Discovery date | October 10, 2004 |
| Designations | |
| P/2004 TU12 | |
| Orbital characteristics[2] | |
| Epoch | 27 October 2010 |
| Aphelion | 4.873 AU |
| Perihelion | 1.233 AU |
| Semi-major axis | 3.053 AU |
| Eccentricity | 0.5961 |
| Orbital period | 5.33 years |
| Inclination | 27.817° |
| Last perihelion | 7 December 2020 |
| Next perihelion | 17 May 2026 |
| TJupiter | 2.792 |
| Earth MOID | 0.239 AU |
| Physical characteristics | |
| Dimensions | 14.06 ± 0.96 km[3] |
| 32.86 hours[4] | |
| 0.022 ± 0.003[4] | |
| Comet total magnitude (M1) | 15.2 |
162P/Siding Spring is a Jupiter-family comet with an orbital period of 5.3 years. It was discovered in images obtained on 10 October 2004 as part of the Siding Spring Survey.[1]
The comet was discovered during the Siding Spring Survey as an asteroidal object shining with an apparent magnitude of 14.1 but a tail extending for about 4 arcminutes was observed on 12 November 2004, indicating that it is a comet.[1] The tail grew longer the next days, reaching a length of over 10 arcminutes on 15 November. Two days later the tail was fainter, and bearly visible within one arcminute from the nucleus.[5] On 21 October 2031 the comet will approach Earth at a distance of 0.2456 AU (36.74 million km).[2]
The comet was observed by NASA Infrared Telescope Facility in 2004, finding that the nucleus has an effective radius of 6.0 ± 0.8 km, which corresponds to a visual albedo of 0.034 ± 0.014,[6] and a reflectance spectrum typical of a D-type asteroid.[7] Further observations by the Spitzer Space Telescope indicate an effective radius of 7.03 ± 0.48 km.[3] This is one of the largest nuclei of Jupiter family comets with known radius.[6] More detailed observations indicate that the nucleus has axis ratios a/b = 1.56 and b/c = 2.33, and could possibly have two lobes.[4] The sidereal period of the comet is 32.864 ± 0.001 hours.[4]
- ^ a b c Mallia, F.; Masi, G.; Wilcox, R.; Lacruz, J. (1 November 2004). "Comet P/2004 TU_12 (Siding Spring)". International Astronomical Union Circular (8436): 1. ISSN 0081-0304.
- ^ a b "Small-Body Database Lookup: 162P/Siding Spring". ssd.jpl.nasa.gov. Retrieved 20 July 2023.
- ^ a b Fernández, Y.R.; Kelley, M.S.; Lamy, P.L.; Toth, I.; Groussin, O.; Lisse, C.M.; A’Hearn, M.F.; Bauer, J.M.; Campins, H.; Fitzsimmons, A.; Licandro, J.; Lowry, S.C.; Meech, K.J.; Pittichová, J.; Reach, W.T.; Snodgrass, C.; Weaver, H.A. (September 2013). "Thermal properties, sizes, and size distribution of Jupiter-family cometary nuclei". Icarus. 226 (1): 1138–1170. arXiv:1307.6191. Bibcode:2013Icar..226.1138F. doi:10.1016/j.icarus.2013.07.021.
- ^ a b c d Donaldson, A; Kokotanekova, R; Rożek, A; Snodgrass, C; Gardener, D; Green, S F; Masoumzadeh, N; Robinson, J (2 March 2023). "Characterizing the nucleus of comet 162P/Siding Spring using ground-based photometry". Monthly Notices of the Royal Astronomical Society. 521 (1): 1518–1531. arXiv:2302.12141. doi:10.1093/mnras/stad616.
- ^ Masi, G. (1 November 2004). "Comet P/2004 TU_12 (Siding Spring)". International Astronomical Union Circular (8439): 1. ISSN 0081-0304.
- ^ a b Fernández, Y. R.; Campins, H.; Kassis, M.; Hergenrother, C. W.; Binzel, R. P.; Licandro, J.; Hora, J. L.; Adams, J. D. (September 2006). "Comet 162P/Siding Spring: A Surprisingly Large Nucleus". The Astronomical Journal. 132 (3): 1354–1360. arXiv:astro-ph/0608387. Bibcode:2006AJ....132.1354F. doi:10.1086/506252.
- ^ Campins, Humberto; Ziffer, Julie; Licandro, Javier; Pinilla-Alonso, Noemí; Fernández, Yanga; León, Julia de; Mothé-Diniz, Thais; Binzel, Richard P. (September 2006). "Nuclear Spectra of Comet 162P/Siding Spring (2004 TU12)". The Astronomical Journal. 132 (3): 1346–1353. Bibcode:2006AJ....132.1346C. doi:10.1086/506253.