78 Diana

78 Diana
	Orbital diagram
Discovery
Discovered by	Karl Theodor Robert Luther
Discovery date	March 15, 1863
Designations
MPC designation	(78) Diana
Pronunciation	/daɪˈænə, daɪˈeɪnə/ dy-A(Y)N-ə
Named after	Diāna (Roman mythology)
Minor planet category	Main belt
Adjectives	Dianian (/daɪˈeɪniən/ dy-AY-nee-ən)
Orbital characteristics
	Epoch December 31, 2006 (JD 2454100.5)
Aphelion	473.182 Gm (3.163 AU)
Perihelion	310.686 Gm (2.077 AU)
Semi-major axis	391.934 Gm (2.620 AU)
Eccentricity	0.207
Orbital period (sidereal)	1,548.922 d (4.24 yr)
Average orbital speed	18.20 km/s
Mean anomaly	353.808°
Inclination	8.688°
Longitude of ascending node	333.582°
Argument of perihelion	151.423°
Physical characteristics
Dimensions	123.63±4.57 km
Mass	(1.27±0.13)×1018 kg
Mean density	1.28±0.19 g/cm3
Synodic rotation period	7.2991 h
Geometric albedo	0.071
Spectral type	C
Absolute magnitude (H)	8.09

78 Diana is a large and dark main-belt asteroid. It was discovered by German astronomer Robert Luther on March 15, 1863,^[6] and named after Diana, Roman goddess of the hunt. The asteroid is orbiting the Sun at a distance of 2.620 AU with a period of 4.24 years and an eccentricity (ovalness) of 0.207. The orbital plane is tilted at an angle of 8.688° relative to the plane of the ecliptic.^[2] Its composition is carbonaceous and primitive.

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] 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.

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

^ "Diana". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
^ ^a ^b Yeomans, Donald K., "78 Diana", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 30 March 2013.
^ ^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". Archived from the original on 17 December 2009. Retrieved 13 January 2007.
^ "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 7 April 2013.
^ 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. Archived from the original (PDF) on 4 July 2008.

External links

78 Diana at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
78 Diana at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

[1] "Diana". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)

[JPL-2] Yeomans, Donald K., "78 Diana", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 30 March 2013.

[Carry2012-3] 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.

[Radeva2011-4] 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.

[5] "Asteroid Data Sets". Archived from the original on 17 December 2009. Retrieved 13 January 2007.

[IAU_MPC-6] "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 7 April 2013.

[Magri2001-7] 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.

[Giorgini2002-8] 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. Archived from the original (PDF) on 4 July 2008.

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