2009 SE

2009 SE
Discovery
Discovered byCatalina Sky Survey
Discovery date16 September 2009
Designations
2009 SE
Martian L5 Martian L5
Orbital characteristics[1]
Epoch 21 November 2025 (JD 2461000.5)
Uncertainty parameter 0
Observation arc5,498 days (15.05 yr)
Aphelion1.623690 AU (242.9006 Gm)
Perihelion1.425183 AU (213.2043 Gm)
1.524436 AU (228.0524 Gm)
Eccentricity0.0651085
1.88 yr (687.484 d)
208.166°
0° 31m 25.136s /day
Inclination20.6248°
6.79202°
354.169°
Earth MOID0.42305 AU (63.287 Gm)
Jupiter MOID3.53237 AU (528.435 Gm)
Physical characteristics
400 m
0.5–0.05 (assumed)
20.13

2009 SE is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2]

Discovery, orbit and physical properties

2009 SE was first observed on 16 September 2009 by the Catalina Sky Survey (CSS).[3] Its orbit is characterized by low eccentricity (0.065), moderate inclination (20.6°) and a semi-major axis of 1.52 AU.[3] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is well determined as it is currently (as of November 2025) based on 60 observations with a data-arc span of 5,498 days.[1] 2009 SE has an absolute magnitude of 20.13 which gives a characteristic diameter of 400 m.[1]

Mars trojan and orbital evolution

Recent calculations indicate that it is a stable L5 Mars trojan with a libration period of 1430 yr and an amplitude of 70°.[2] The libration amplitude is not similar to that of 5261 Eureka and related objects.[citation needed]

See also

References

Further reading