| Discovery | |
|---|---|
| Discovered by | Mt. Lemmon Survey |
| Discovery date | 29 September 2011 |
| Designations | |
| 2011 SP189 | |
Martian L5  | |
| Orbital characteristics[1] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 2390 days (6.54 yr) |
| Aphelion | 1.5852549 AU (237.15076 Gm) |
| Perihelion | 1.462275 AU (218.7532 Gm) |
| 1.5237649 AU (227.95198 Gm) | |
| Eccentricity | 0.040354 |
| 1.88 yr (687.0295 d) | |
| 110.302° | |
| 0° 31m 26.382s /day | |
| Inclination | 19.89778° |
| 0.663826° | |
| 122.545° | |
| Earth MOID | 0.490971 AU (73.4482 Gm) |
| Jupiter MOID | 3.40399 AU (509.230 Gm) |
| Physical characteristics | |
| 300 m | |
| 0.5-0.05 (assumed) | |
| 20.9 | |
2011 SP189 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2][3][4]
Discovery, orbit and physical properties
2011 SP189 was first observed on 29 September 2011 by the Mount Lemmon Survey.[5] Its orbit is characterized by low eccentricity (0.040), moderate inclination (19.9°) and a semi-major axis of 1.52 AU.[5] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. It is now classified as a Mars trojan. Its orbit is well determined as it is currently (January 2021) based on 45 observations with a data-arc span of 2390 days.[1] 2011 SP189 has an absolute magnitude of 20.9 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 with a libration period of 1300 yr and an amplitude of 20°.[2] These values are similar to those of 5261 Eureka and related objects and it may 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
See also
References
- ^ a b c "JPL Small-Body Database Browser: (2011 SP189)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
- ^ a b 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.
- ^ a b 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
- 2011 SP189 data at MPC.
- 2011 SP189 at AstDyS-2, Asteroids—Dynamic Site
- 2011 SP189 at ESA–space situational awareness
- 2011 SP189 at the JPL Small-Body Database
