78 Diana

Diana (minor planet designation: 78 Diana) is a large and dark main-belt asteroid that is orbiting the Sun with a period of 4.24 years. Its composition is carbonaceous and primitive. It was discovered by German astronomer Robert Luther on March 15, 1863,[6] 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.

78 Diana
Discovery
Discovered byKarl Theodor Robert Luther
Discovery dateMarch 15, 1863
Designations
(78) Diana
Pronunciation/daɪˈænə, ˈeɪnə/[1]
Named after
Diāna (Roman mythology)
Main belt
AdjectivesDianian /daɪˈeɪniən/
Orbital characteristics[2]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion473.182 Gm (3.163 AU)
Perihelion310.686 Gm (2.077 AU)
391.934 Gm (2.620 AU)
Eccentricity0.207
1548.922 d (4.24 a)
18.20 km/s
353.808°
Inclination8.688°
333.582°
151.423°
Physical characteristics
Dimensions123.63 ± 4.57 km[3]
Mass(1.27 ± 0.13) × 1018 kg[3]
Mean density
1.28 ± 0.19[3] g/cm3
7.2991[4] h
0.071 [5]
C
8.09

    Photometric observations of this asteroid during 1986 and 2006–08 gave a light curve with a rotation period of 7.2991 hours and a brightness variation in the range 0.02–0.104 magnitude.[4] Based upon radar data, the near surface solid density of the asteroid is 2.7+0.8
    −0.5     g cm−3.[7]

    Diana is expected to pass about 0.003 AU (450,000 km; 280,000 mi) from (29075) 1950 DA on August 5, 2150.[8] 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.[8]

    References
    1. "Diana". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
    2. Yeomans, Donald K., "78 Diana", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 30 March 2013.
    3. Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
    4. Radeva, V.; et al. (2011), "Rotation periods of the asteroids 55 Pandora, 78 Diana and 815 Coppelia", Bulgarian Astronomical Journal, 17, pp. 133–141, Bibcode:2012MPBu...39...57P.
    5. Asteroid Data Sets Archived 2010-01-17 at WebCite
    6. "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 7 April 2013.
    7. Magri, C.; et al. (December 2001), "Radar constraints on asteroid regolith compositions using 433 Eros as ground truth", Meteoritics & Planetary Science, 36 (12), pp. 1697–1709, Bibcode:2001M&PS...36.1697M, doi:10.1111/j.1945-5100.2001.tb01857.x.
    8. Giorgini, J. D.; Ostro, S. J.; Benner, L. A. M.; Chodas, P.W.; Chesley, S.R.; Hudson, R. S.; et al. (2002). "Asteroid 1950 DA's Encounter With Earth in 2880: Physical Limits of Collision Probability Prediction" (PDF). Science. 296 (5565): 132–136. Bibcode:2002Sci...296..132G. doi:10.1126/science.1068191. PMID 11935024.


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