 The comet on 12 November 2004, displaying a narrow tail | |
| Discovery1 | |
|---|---|
| Discovery site | Siding Spring Observatory |
| Discovery date | 10 October 2004 |
| Designations | |
| P/2004 TU12 | |
| Orbital characteristics23 | |
| 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 km4 |
| 32.864±0.001 hours5 | |
| 0.022±0.0035 | |
| (V–R) = 0.45±0.016 | |
| 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
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
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
See also
- 107P/Wilson-Harrington and 133P/Elst-Pizarro - comets with similar intermittent activity
References
References
- 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.
- "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.
- 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.2013.07.021.
- 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.
- 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
External links
- 162P/Siding Spring at the JPL Small-Body Database
- 162P/Siding Spring at Seiichi Yoshida's website
- 162P/Siding Spring at Gideon van Buitenen's website
- Cometary activity found on asteroidal object 2004 TU12 - La Cañada Observatory report