354 Eleonora
Main-belt asteroid
From Wikipedia, the free encyclopedia
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] This asteroid is orbiting the Sun at a distance of 2.80 AU with a moderate eccentricity (ovalness) of 0.11 and an orbital period of 4.68 years. The orbital plane is inclined at an angle of 18.4° to the plane of the ecliptic.[2]
 | |
| Discovery | |
|---|---|
| Discovered by | Auguste Charlois |
| Discovery date | 17 January 1893 |
| Designations | |
| (354) Eleonora | |
| Pronunciation | /ÉliÉËnÉËrÉ/[1] |
| 1893 A | |
| Main belt | |
| Adjectives | Eleonorian |
| Orbital characteristics[2] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 123.16 yr (44983 d) |
| Aphelion | 3.1188 AU (466.57 Gm) |
| Perihelion | 2.47676 AU (370.518 Gm) |
| 2.79777 AU (418.540 Gm) | |
| Eccentricity | 0.11474 |
| 4.68 yr (1709.3 d) | |
| 123.762° | |
| 0° 12m 38.196s / day | |
| Inclination | 18.403° |
| 140.37° | |
| 5.5215° | |
| Physical characteristics | |
| Dimensions | 0.25[a] |
| 165±3 km[3] 154.3±5.6 km[4] 148.970±0.425 km[5][2] | |
| Mass | (7.5±2.7)Ã1018 kg[3] (7.18±2.57)Ã1018 kg[4] (6.236 ± 1.305/1.214)Ã1018 kg[5] |
Mean density | 3.18±1.14 g/cm3[3] 3.73±1.39 g/cm3[4] 3.602 ± 0.754/0.701 g/cm3[5] |
| 4.277 h (0.1782 d)[2] | |
| 0.172[3] 0.201±0.052[2] | |
| S | |
| 6.15[2] | |
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 a stony 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] The surface spectrum is consistent with fine-grained material consisting of 60â70% olivine and 7â8% nickel.[9]
During favorable oppositions, such as in 1968 and 2010, Eleonora can reach an apparent magnitude of +9.31.
