Astronomy:354 Eleonora

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354 Eleonora
Discovery
Discovered byAuguste Charlois
Discovery date17 January 1893
Designations
(354) Eleonora
Pronunciation/ɛliəˈnɔːrə/[1]
1893 A
Minor planet categoryMain belt
AdjectivesEleonorian
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc123.16 yr (44983 d)
|{{{apsis}}}|helion}}3.1188 astronomical unit|AU (466.57 Gm)
|{{{apsis}}}|helion}}2.47676 AU (370.518 Gm)
2.79777 AU (418.540 Gm)
Eccentricity0.11474
Orbital period4.68 yr (1709.3 d)
Mean anomaly123.762°
Mean motion0° 12m 38.196s / day
Inclination18.403°
Longitude of ascending node140.37°
5.5215°
Physical characteristics
Dimensions0.25[lower-alpha 1]
Mean diameter165±3 km[3]
154.3±5.6 km[4]
148.970±0.425 km[5][2]
Mass(7.5±2.7)×1018 kg[3]
(7.18±2.57)×1018 kg[4]
Template:Nwr
Mean density3.18±1.14 g/cm3[3]
3.73±1.39 g/cm3[4]
3.602 ± 0.754/0.701 g/cm3[5]
Rotation period4.277 h (0.1782 d)[2]
Geometric albedo0.172[3]
0.201±0.052[2]
S
Absolute magnitude (H)6.15[2]


354 Eleonora is a large, stony main-belt asteroid that was discovered by the French astronomer Auguste Charlois on January 17, 1893, in Nice.[6]

Photometric observations of this asteroid gave a light curve with a period of 13.623 hours. The data was used to construct a model for the asteroid, revealing it to be a regular-shaped object, spinning about a pole with ecliptic coordinates (β, λ) = (+20°, 356°), although this is with an accuracy of only ±10°. The ratio of the major to minor axes lengths is roughly equal to 1.2.[7] It is classified as an S-type asteroid and has an estimated size of 154.34 km.[4] The spectrum of 354 Eleonora reveals the strong presence of the mineral olivine, a relative rarity in the asteroid belt.[8]

During favorable oppositions, such as in 1968 and 2010, Eleonora can reach an apparent magnitude of +9.31.

Notes

  1. Flattening derived from the maximum aspect ratio (c/a): f=1ca, where (c/a) = 0.75±0.08.[3]

References

  1. Eleonora (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Eleonora  (Subscription or UK public library membership required.)
  2. 2.0 2.1 2.2 2.3 2.4 Yeomans, Donald K., "354 Eleonora", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=354, retrieved 11 May 2016. 
  3. 3.0 3.1 3.2 3.3 3.4 P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
  4. 4.0 4.1 4.2 4.3 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73 (1): 98–118, doi:10.1016/j.pss.2012.03.009, Bibcode2012P&SS...73...98C.  See Table 1.
  5. 5.0 5.1 Fienga, A.; Avdellidou, C.; Hanuš, J. (February 2020). "Asteroid masses obtained with INPOP planetary ephemerides". Monthly Notices of the Royal Astronomical Society 492 (1). doi:10.1093/mnras/stz3407. https://academic.oup.com/mnras/article/492/1/589/5658701. 
  6. "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html, retrieved 2013-04-07. 
  7. Kaasalainen, M. et al. (October 2002), "Models of Twenty Asteroids from Photometric Data", Icarus 159 (2): 369–395, doi:10.1006/icar.2002.6907, Bibcode2002Icar..159..369K. 
  8. Burbine, T. H. et al. (July 2000), "The Nature of Olivine Asteroids", Meteoritics & Planetary Science 35: pp. A35, doi:10.1111/j.1945-5100.2000.tb01796.x, Bibcode2000M&PSA..35R..35B.