Discovery | |
---|---|
Discovered by | Mt. Lemmon Survey |
Discovery date | 29 September 2011 |
Designations | |
MPC designation | 2011 SP189 |
Minor planet category | Martian L5 |
Orbital characteristics | |
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) |
Semi-major axis | 1.5237649 AU (227.95198 Gm) |
Eccentricity | 0.040354 |
Orbital period (sidereal) | 1.88 yr (687.0295 d) |
Mean anomaly | 110.302° |
Mean motion | 0° 31 26.382 /day |
Inclination | 19.89778° |
Longitude of ascending node | 0.663826° |
Argument of perihelion | 122.545° |
Earth MOID | 0.490971 AU (73.4482 Gm) |
Jupiter MOID | 3.40399 AU (509.230 Gm) |
Physical characteristics | |
Mean diameter | 300 m |
Geometric albedo | 0.5-0.05 (assumed) |
Absolute magnitude (H) | 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).
Discovery, orbit and physical properties
2011 SP189 was first observed on 29 September 2011 by the Mount Lemmon Survey. Its orbit is characterized by low eccentricity (0.040), moderate inclination (19.9°) and a semi-major axis of 1.52 AU. 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 45 observations with a data-arc span of 2390 days. 2011 SP189 has an absolute magnitude of 20.9 which gives a characteristic diameter of 300 m.
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°. 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
- 2009 SE
- 2011 SC191
- 2011 SL25
- 2011 SP189
- 2011 UB256
- 2011 UN63
- 2016 CP31
- 2018 EC4
- 2018 FC4
See also
References
- ^ "JPL Small-Body Database Browser: (2011 SP189)". 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
- 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
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