78 Diana

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78 Diana
Discovery
Discovered by Karl Theodor Robert Luther
Discovery date March 15, 1863
Designations
Named after
Diana
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 473.182 Gm (3.163 AU)
Perihelion 310.686 Gm (2.077 AU)
391.934 Gm (2.620 AU)
Eccentricity 0.207
1548.922 d (4.24 a)
18.20 km/s
353.808°
Inclination 8.688°
333.582°
151.423°
Physical characteristics
Dimensions 123.63 ± 4.57[2] km
Mass (1.27 ± 0.13) × 1018[2] kg
Mean density
1.28 ± 0.19[2] g/cm3
0.0337 m/s²
0.0638 km/s
7.2991[3] h
Albedo 0.071 [4]
Temperature ~172 K
Spectral type
C
8.09

78 Diana (dye-an'-a) is a large and dark main-belt asteroid. Its composition is carbonaceous and primitive. It was discovered by Robert Luther on March 15, 1863,[5] and named after Diana, Roman goddess of the hunt. 78 Diana occulted a star on September 4, 1980. A diameter of 116 km was measured, closely matching the value given by the IRAS satellite.

Photometric observations of this asteroid during 1986 and 2006–08 gave a light curve with a period of 7.2991 hours and a brightness variation in the range 0.02–0.104 magnitude.[3] Based upon radar data, the near surface solid density of the asteroid is 2.7+0.8
−0.5
g cm–3.[6]

Diana is expected to pass about 0.003 AU (450,000 km; 280,000 mi) from (29075) 1950 DA on August 5, 2150.[7] Main-belt asteroid 4217 Engelhardt (~9 km in diameter) will pass about 0.0017 AU (250,000 km; 160,000 mi) from (29075) 1950 DA in 2736.[7]

References[edit]

  1. ^ Yeomans, Donald K., "78 Diana", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-30. 
  2. ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009.  See Table 1.
  3. ^ a b Radeva, V. et al. (2011), "Rotation periods of the asteroids 55 Pandora, 78 Diana and 815 Coppelia", Bulgarian Astronomical Journal 17: 133–141, Bibcode:2012MPBu...39...57P. 
  4. ^ Asteroid Data Sets
  5. ^ "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), retrieved 2013-04-07. 
  6. ^ Magri, C. et al. (December 2001), "Radar constraints on asteroid regolith compositions using 433 Eros as ground truth", Meteoritics & Planetary Science 36 (12): 1697–1709, Bibcode:2001M&PS...36.1697M, doi:10.1111/j.1945-5100.2001.tb01857.x. 
  7. ^ a b Giorgini, J. D.; Ostro, S. J; Benner, L. A. M.; Chodas, P.W.; Chesley, S.R.; Hudson, R. S.; Nolan, M. C.; Klemola, A. R.; Standish, E. M.; Jurgens, R. F.; Rose, R.; Chamberlin, A. B.; Yeomans, D. K.; Margot, J.-L. (2002). "Asteroid 1950 DA's Encounter With Earth in 2880: Physical Limits of Collision Probability Prediction". Science 296 (5565): 132–136. Bibcode:2002Sci...296..132G. doi:10.1126/science.1068191. PMID 11935024.