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 barely 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]
^ abFernández, 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.
.png)
