| Discovery | |
|---|---|
| Discovered by | Pan-STARRS |
| Discovery date | 29 October 2011 |
| Designations | |
Martian L5  | |
| Orbital characteristics1 | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 6265 days (17.15 yr) |
| Aphelion | 1.631894031 AU (244.1278722 Gm) |
| Perihelion | 1.4154896 AU (211.75423 Gm) |
| 1.523691798 AU (227.9410486 Gm) | |
| Eccentricity | 0.0710132 |
| 1.88 yr (686.980044 d) | |
| 180.60444° | |
| 0° 31m 26.518s /day | |
| Inclination | 24.30270° |
| 58.781126° | |
| 7.58178° | |
| Earth MOID | 0.428887 AU (64.1606 Gm) |
| Jupiter MOID | 3.5641 AU (533.18 Gm) |
| Physical characteristics | |
| 300 m | |
| 0.5-0.05 (assumed) | |
| 19.9 | |
2011 UB256 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).234
Discovery, orbit and physical properties
2011 UB256 was first observed on 29 October 2011 by the Pan-STARRS 1 telescope system at Haleakala; the Apache Point-Sloan Digital Sky Survey had imaged this object on 31 March 2003 without identifying it as an asteroid.5 Its orbit is characterized by low eccentricity (0.071), moderate inclination (24.3°) and a semi-major axis of 1.52 AU.5 Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is well determined as it is currently (January 2021) based on 64 observations with a data-arc span of 6265 days.1 2011 UB256 has an absolute magnitude of 19.9 which gives a characteristic diameter of 300 m.1
Mars trojan and orbital evolution
Recent calculations indicate that it is a stable L5 Mars trojan.2 It may not be a member of the so-called Eureka family.
Mars trojan
L4 (leading):
L5 (trailing):
- 5261 Eureka (1990 MB) †
- (101429) 1998 VF31 †
- (311999) 2007 NS2 †
- (385250) 2001 DH47
- (816688) 2011 SC191
- 2009 SE
- 2011 SL25
- 2011 SP189
- 2011 UB256
- 2011 UN63
- 2016 CP31
- 2018 EC4
- 2018 FC4
References
References
- "JPL Small-Body Database Browser: (2011 UB256)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
- Christou, Apostolos A.; Borisov, Galin; Dell'Oro, Aldo; Jacobson, Seth A.; Cellino, Alberto; Unda-Sanzana, Eduardo (January 2020). "Population control of Mars Trojans by the Yarkovsky & YORP effects". Icarus. 335 (1): 113370 (34 pages). arXiv:1907.12858. Bibcode:2020Icar..33513370C. doi:10.1016/j.icarus.2019.07.004. S2CID 198985887.
- Christou, Apostolos A.; Borisov, Galin; Dell'Oro, Aldo; Cellino, Alberto; Devogèle, Maxime (January 2021). "Composition and origin of L5 Trojan asteroids of Mars: Insights from spectroscopy". Icarus. 354 (1): 113994 (22 pages). arXiv:2010.10947. Bibcode:2021Icar..35413994C. doi:10.1016/j.icarus.2020.113994. S2CID 224814529.
- de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.
- MPC data on 2011 SP189
- Further reading
- Three new stable L5 Mars Trojans de la Fuente Marcos, C., de la Fuente Marcos, R. 2013, Monthly Notices of the Royal Astronomical Society: Letters, Vol. 432, Issue 1, pp. 31–35.
- Orbital clustering of Martian Trojans: An asteroid family in the inner solar system? Christou, A. A. 2013, Icarus, Vol. 224, Issue 1, pp. 144–153.
External links
External links
- 2011 UB256 data at MPC.
- 2011 UB256 at AstDyS-2, Asteroids—Dynamic Site
- 2011 UB256 at ESA–space situational awareness
- 2011 UB256 at the JPL Small-Body Database