59 Elpis

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.^[6]

59 Elpis

Orbital diagram
Discovery
Discovered by	Jean Chacornac
Discovery date	September 12, 1860
Designations
MPC designation	(59) Elpis
Pronunciation	/ˈɛlpɪs/[1]
Named after	Elpis
Minor planet category	Main belt
Adjectives	Elpidian /ɛlˈpɪdiən/[2]
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°
Argument of perihelion	210.901°
Physical characteristics
Dimensions	164.8±6.0 km[3]
Mass	(3.00±0.50)×1018 kg[4]
Mean density	1.30±0.26 g/cm3[4]
Synodic rotation period	13.69 h[3]
Geometric albedo	0.044[3][5]
Spectral type	CP/B[3]
Absolute magnitude (H)	7.93[3]

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.^[7] However, Elpis is the name that stuck.^[8]

Elpis has been studied by radar.^[9]