78 Diana
Discovery | |
---|---|
Discovered by | Karl Theodor Robert Luther |
Discovery date | March 15, 1863 |
Designations | |
Named after | Diana |
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) | |
Average orbital speed | 18.20 km/s |
353.808° | |
Inclination | 8.688° |
333.582° | |
151.423° | |
Physical characteristics | |
Dimensions | 123.63 ± 4.57 km[2] |
Mass | (1.27 ± 0.13) × 1018 kg[2] |
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
- ^ Yeomans, Donald K., "78 Diana", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 2013-03-30.
- ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, vol. 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
- ^ a b Radeva, V.; et al. (2011), "Rotation periods of the asteroids 55 Pandora, 78 Diana and 815 Coppelia", Bulgarian Astronomical Journal, vol. 17, pp. 133–141, Bibcode:2012MPBu...39...57P.
- ^ Asteroid Data Sets
- ^ "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 2013-04-07.
- ^ Magri, C.; et al. (December 2001), "Radar constraints on asteroid regolith compositions using 433 Eros as ground truth", Meteoritics & Planetary Science, vol. 36, no. 12, pp. 1697–1709, Bibcode:2001M&PS...36.1697M, doi:10.1111/j.1945-5100.2001.tb01857.x.
- ^ a b 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.
External links
- 78 Diana at the JPL Small-Body Database