59 Elpis
Elpis, minor planet designation: 59 Elpis, is a large main belt asteroid that orbits the Sun with a period of 4.47 years. It is a C-type asteroid, meaning that it is very dark and carbonaceous in composition. In the Tholen scheme it has a classification of CP, while Bus and Binzen class it as type B.
Orbital diagram | |
Discovery | |
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Discovered by | Jean Chacornac |
Discovery date | September 12, 1860 |
Designations | |
MPC designation | (59) Elpis |
Pronunciation | /ˈɛlpɪs/ |
Named after | Elpis |
Minor planet category | Main belt |
Adjectives | Elpidian /ɛlˈpɪdiən/ |
Orbital characteristics | |
Epoch December 31, 2006 (JD 2454100.5) | |
Aphelion | 453.624 Gm (3.032 AU) |
Perihelion | 358.808 Gm (2.398 AU) |
Semi-major axis | 406.216 Gm (2.715 AU) |
Eccentricity | 0.117 |
Orbital period (sidereal) | 1634.355 d (4.47 a) |
Mean anomaly | 246.848° |
Inclination | 8.631° |
Longitude of ascending node | 170.209° |
210.901° | |
Physical characteristics | |
Dimensions | 164.8±6.0 km |
Mass | (3.00±0.50)×1018 kg |
Mean density | 1.30±0.26 g/cm3 |
Synodic rotation period | 13.69 h |
0.044 | |
CP/B | |
7.93 | |
Elpis was discovered by Jean Chacornac from Paris, on September 12, 1860. It was Chacornac's sixth and final asteroid discovery.
A controversy arose over the naming of Elpis. Urbain Le Verrier, director of the Paris Observatory, at first refused to allow Chacornac to name the object, because Leverrier was promoting a plan to reorganize asteroid nomenclature by naming them after their discoverers, rather than mythological figures. A protest arose among astronomers. At the Vienna Observatory, Edmund Weiss, who had been studying the asteroid, asked the observatory's director, Karl L. Littrow, to name it. Littrow chose Elpis, a Greek personification of hope, in reference to the favorable political conditions in Europe at the time. In 1862, Leverrier permitted Chacornac to choose a name, and he selected "Olympia" at the suggestion of John Russell Hind. However, Elpis is the name that stuck.
Elpis has been studied by radar.