2011 UB256
Discovery
Discovered byPan-STARRS
Discovery date29 October 2011
Designations
2011 UB256
Martian L5 Martian L5
Orbital characteristics[1]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc6265 days (17.15 yr)
Aphelion1.631894031 AU (244.1278722 Gm)
Perihelion1.4154896 AU (211.75423 Gm)
1.523691798 AU (227.9410486 Gm)
Eccentricity0.0710132
1.88 yr (686.980044 d)
180.60444°
0° 31m 26.518s /day
Inclination24.30270°
58.781126°
7.58178°
Earth MOID0.428887 AU (64.1606 Gm)
Jupiter MOID3.5641 AU (533.18 Gm)
Physical characteristics
Mean diameter
300 m
0.5-0.05 (assumed)
19.9

2011 UB256 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 UB256 was first observed on 29 October 2011 by the Pan-STARRS 1 telescope system at Haleakala; the Apache Point-Sloan Digital Sky Survey had imaged this object on 31 March 2003 without identifying it as an asteroid.[5] Its orbit is characterized by low eccentricity (0.071), moderate inclination (24.3°) and a semi-major axis of 1.52 AU.[5] 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 64 observations with a data-arc span of 6265 days.[1] 2011 UB256 has an absolute magnitude of 19.9 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.[2] It may not be a member of the so-called Eureka family.

Mars trojan

L4 (leading):

L5 (trailing):

See also

References

  1. ^ a b c "JPL Small-Body Database Browser: (2011 UB256)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.
  5. ^ a b MPC data on 2011 SP189
Further reading

External links

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