2011 QF99
| Discovery | |
|---|---|
| Discovery date | 2011 [1] |
| Designations | |
| centaur | |
| Orbital characteristics [2] | |
| Epoch JD 2457000.5 (2014-Dec-09) | |
| Aphelion | 22.526 AU |
| Perihelion | 15.707 AU |
| 19.117 AU | |
| Eccentricity | 0.17835 |
| 83.59 yr (30,530 ± 4 d) | |
| 273.36° | |
| Inclination | 10.8119° |
| 222.5071° | |
| 287.04° | |
| Physical characteristics | |
| Dimensions | ~ 60 km [2] |
| Albedo | 0.05 (assumed) |
|
9.6 (r-band) [2] 9.7 [1] | |
|
| |
2011 QF99 is the first and, as of 2015, the only known Uranus trojan.[2][3] It was discovered in 2011 during a deep survey of trans-Neptunian objects conducted with the Canada–France–Hawaii Telescope.[2][4] It is believed to be roughly 60 km in diameter, assuming an albedo of 0.05.[2]
2011 QF99 temporarily orbits near Uranus's L4 Langrangian point (leading Uranus). It will continue to librate around L4 for at least 70,000 years and will remain a Uranus co-orbital for up to three million years before becoming a centaur. 2011 QF99 is thus a temporary Uranus trojan—a centaur captured some time ago.[2]
Uranus trojans are generally expected to be unstable and none of them are thought to be of primordial origin. A simulation led to the conclusion that at any given time, 0.4% of the centaurs in the scattered population within 34 AU would be Uranus co-orbitals, of which 64% (0.256% of all centaurs) would be in horseshoe orbits, 10% (0.04%) would be quasi-satellites, and 26% (0.104%) would be trojans (evenly split between the L4 and L5 groups).[2]
References
- 1 2 "JPL Small-Body Database Browser: 2011 QF99". Retrieved 2013-03-29.
- 1 2 3 4 5 6 7 8 Alexandersen, M.; Gladman, B.; Greenstreet, S.; Kavelaars, J. J.; Petit, J. -M.; Gwyn, S. (2013). "A Uranian Trojan and the Frequency of Temporary Giant-Planet Co-Orbitals". Science 341 (6149): 994–997. arXiv:1303.5774. doi:10.1126/science.1238072. PMID 23990557.
- ↑ Choi, C. Q. (2013-08-29). "First 'Trojan' Asteroid Companion of Uranus Found". Space.com web site. TechMediaNetwork. Retrieved 2013-09-03.
- ↑ Alexandersen, M.; Kavelaars, J.; Petit, J.; Gladman, B. (18 March 2013). "MPEC 2013-F19: 2011 QF99". IAU. Retrieved 3 September 2013.
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