162P/Siding Spring
| The comet on 12 November 2004, displaying a narrow tail | |
| Discovery[1] | |
|---|---|
| Discovery site | Siding Spring Observatory |
| Discovery date | 10 October 2004 |
| Designations | |
| P/2004 TU12 | |
| Orbital characteristics [2] [3] | |
| Epoch | 5 May 2025 (JD 2460800.5) |
| Observation arc | 35.27 years |
| Earliest precovery date | 23 March 1990 |
| Number of observations | 3,273 |
| Aphelion | 4.894 AU |
| Perihelion | 1.289 AU |
| Semi-major axis | 3.092 AU |
| Eccentricity | 0.58295 |
| Orbital period | 5.33 years |
| Inclination | 27.554° |
| 30.878° | |
| Argument of periapsis | 357.24° |
| Mean anomaly | 291.51° |
| Last perihelion | 7 December 2020 |
| Next perihelion | 17 May 2026 |
| TJupiter | 2.792 |
| Earth MOID | 0.239 AU |
| Jupiter MOID | 0.587 AU |
| Physical characteristics | |
Mean diameter | 14.06±0.96 km[4] |
| 32.864±0.001 hours[5] | |
| 0.022±0.003[5] | |
| (V–R) = 0.45±0.01[6] | |
| 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]
Observational history
[edit ]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.[7] On 21 October 2031, the comet will approach Earth at a distance of 0.2456 AU (36.74 million km).[2]
Physical characteristics
[edit ]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,[8] and a reflectance spectrum typical of a D-type asteroid.[9] Further observations by the Spitzer Space Telescope indicate an effective radius of 7.03 ± 0.48 km.[4] This is one of the largest nuclei of Jupiter family comets with known radius.[8] 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.[5] The sidereal period of the comet is 32.864±0.001 hours.[5]
See also
[edit ]- 107P/Wilson-Harrington and 133P/Elst-Pizarro - comets with similar intermittent activity
References
[edit ]- ^ a b c F. Mallia; G. Masi; R. Wilcox; J. Lacruz (1 November 2004). D. W. Green (ed.). "Comet P/2004 TU12 (Siding Spring)". IAU Circular (8436). Bibcode:2004IAUC.8436....1M. ISSN 0081-0304.
- ^ a b "162P/Siding Spring – JPL Small-Body Database Lookup". ssd.jpl.nasa.gov. Jet Propulsion Laboratory . Retrieved 20 July 2023.
- ^ "162P/Siding Spring Orbit". Minor Planet Center . Retrieved 25 July 2025.
- ^ a b Y. R. Fernández; M. S. P. Kelley; P. L. Lamy; I. Toth; O. Groussin; et al. (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年07月02日1.
- ^ a b c d A. Donaldson; R. Kokotanekova; A. Rożek; C. Snodgrass; et al. (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 .
- ^ M. M. Knight; R. Kokotanekova; N. H. Samarasinha (2023). "Physical and Surface Properties of Comet Nuclei from Remote Observations". arXiv:2304.09309 [astro-ph.EP].
- ^ G. Masi (1 November 2004). D. W. Green (ed.). "Comet P/2004 TU12 (Siding Spring)". IAU Circular (8439). Bibcode:2004IAUC.8439....1M. ISSN 0081-0304.
- ^ a b Y. R. Fernández; H. Campins; M. Kassis; C. W. Hergenrother; et al. (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 .
- ^ H. Campins; J. Ziffer; J. Licandro; N. Pinilla-Alonso; et al. (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.
External links
[edit ]- 162P/Siding Spring at the JPL Small-Body Database
- Cometary activity found on asteroidal object 2004 TU12 - La Cañada Observatory report
| Numbered comets | ||
|---|---|---|
| Previous 161P/Hartley–IRAS |
162P/Siding Spring | Next 163P/NEAT |
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