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2011 SL25, also written as 2011 SL25, is an asteroid and Mars trojan candidate that shares the orbit of the planet Mars at its L5 point.[2]

2011 SL25
Discovery dateSeptember 21, 2011
MPC designation2011 SL25
Martian L5 Martian L5
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 2
Observation arc1637 days (4.48 yr)
Aphelion1.698231 AU (254.0517 Gm)
Perihelion1.349540 AU (201.8883 Gm)
1.523885 AU (227.9700 Gm)
1.88 yr (687.11 d)
0° 31m 26.159s /day
Earth MOID0.396438 AU (59.3063 Gm)
Jupiter MOID3.52931 AU (527.977 Gm)
Physical characteristics
Dimensions550 ± 230 m
0.5-0.05 (assumed)


Discovery, orbit and physical propertiesEdit

2011 SL25 was discovered on 21 September 2011 at the Alianza S4 Observatory on Cerro Burek in Argentina [3] and classified as Mars-crosser by the Minor Planet Center. It follows a relatively eccentric orbit (0.11) with a semi-major axis of 1.52 AU.[3] This object has noticeable orbital inclination (21.5°).[3] Its orbit was initially poorly constrained, with only 76 observations over 42 days, but was recovered in January 2014.[1] 2011 SL25 has an absolute magnitude of 19.5 which gives a characteristic diameter of 575 m.[1]

Mars trojan candidate and orbital evolutionEdit

Recent calculations indicate that it is a stable L5 Mars Trojan candidate with a libration period of 1400 yr and an amplitude of 18°.[2][4] values as well as its short-term orbital evolution are similar to those of 5261 Eureka.


Long-term numerical integrations show that its orbit is stable on Gyr time-scales (1 Gyr = 1 billion years). It appears to be stable at least for 4.5 Gyr but its current orbit indicates that it has not been a dynamical companion to Mars for the entire history of the Solar System.[2]

See alsoEdit


  1. ^ a b c "JPL Small-Body Database Browser: (2011 SL25)". Jet Propulsion Laboratory. Retrieved 31 March 2016.
  2. ^ a b c de la Fuente Marcos, C.; de la Fuente Marcos, R. (April 2013). "Three new stable L5 Mars Trojans". Monthly Notices of the Royal Astronomical Society: Letters. 432 (1): L31–L35. arXiv:1303.0124. Bibcode:2013MNRAS.432L..31D. doi:10.1093/mnrasl/slt028.
  3. ^ a b c MPC data on 2011 SL25
  4. ^ Christou, A. A. (2013). "Orbital clustering of Martian Trojans: An asteroid family in the inner solar system?". Icarus. 224 (1): 144–153. arXiv:1303.0420. Bibcode:2013Icar..224..144C. doi:10.1016/j.icarus.2013.02.013.
Further reading

External linksEdit