|Discovery date||September 21, 2011|
|MPC designation||2011 SL25|
|Minor planet category||Martian L5|
|Epoch April 18, 2013 (JD 2456400.5)|
|Semi-major axis||1.5239213 AU|
|Orbital period||1.88 yr|
|Longitude of ascending node||9.42731°|
|Argument of perihelion||53.29126°|
|Absolute magnitude (H)||19.5|
Discovery, orbit and physical properties
2011 SL25 was discovered on September 21, 2011 at the Alianza S4 Observatory on Cerro Burek in Argentina  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. This object has noticeable orbital inclination (21.5º). Its orbit is still not very well constrained as it is currently (March 2013) based on 76 observations with a data-arc span of just 42 days. 2011 SL25 is an asteroid with an absolute magnitude of 19.5 which gives a characteristic diameter of 575 m.
Mars trojan candidate and orbital evolution
Recent calculations indicate that it is a stable L5 Mars Trojan candidate with a libration period of 1400 yr and an amplitude of 18º. 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.
- 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.
- MPC data on 2011 SL25
- JPL's Solar System Dynamics data on 2011 SL25
- 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
- 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.