(385250) 2001 DH47

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2001 DH47
Discovered by Spacewatch
Discovery date 20 February 2001
MPC designation (385250) 2001 DH47
2001 DH47
Martian L5 Martian L5
Orbital characteristics[1]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc 5521 days (15.12 yr)
Aphelion 1.5767436 AU (235.87749 Gm)
Perihelion 1.4708966 AU (220.04300 Gm)
1.5238201 AU (227.96024 Gm)
Eccentricity 0.0347308
1.88 yr (687.07 d)
0° 31m 26.279s / day
Inclination 24.40220°
Physical characteristics
Mean diameter
0.562 km
3.97 h[1]
0.5–0.05 (assumed)

(385250) 2001 DH47, provisional designation 2001 DH47, is a sub-kilometer asteroid orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).[2][3]

Discovery, orbit and physical properties[edit]

2001 DH47 was discovered on February 1, 2001 by the Spacewatch program, observing from Steward Observatory, Kitt Peak[4] and classified as Mars-crosser by the Minor Planet Center. Its orbit is characterized by low eccentricity (0.035), moderate inclination (24.4º) and a semi-major axis of 1.52 AU.[4] Its orbit is well determined as it is currently (March 2013) based on 45 observations with a data-arc span of 3,148 days,[1] it has an absolute magnitude of 19.7 which gives a characteristic diameter of 562 m.[1]

Mars trojan and orbital evolution[edit]

It was identified as Mars trojan by H. Scholl, F. Marzari and P. Tricarico in 2005 and its dynamical half-lifetime was found to be of the order of the age of the Solar System.[2] Recent calculations [3] confirm that it is indeed a stable L5 Mars trojan with a libration period of 1365 yr and an amplitude of 11°. These values as well as its short-term orbital evolution are very similar to those of 5261 Eureka.


Long-term numerical integrations show that its orbit is very stable on Gyr time-scales (1 Gyr = 1 billion years),[2][3] as in the case of Eureka, calculations in both directions of time (4.5 Gyr into the past and 4.5 Gyr into the future) indicate that 2001 DH47 may be a primordial object, perhaps a survivor of the planetesimal population that formed in the terrestrial planets region early in the history of the Solar System.[3]

See also[edit]


Further reading[edit]

  • 2001 DH47 Ivashchenko, Y., Ostafijchuk, P., Spahr, T. B. 2007, Minor Planet Electronic Circular, 2007-P09.
  • Dynamics of Mars Trojans Scholl, H., Marzari, F., Tricarico, P. 2005, Icarus, Volume 175, Issue 2, p. 397–408.
  • 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.

External links[edit]