11 Parthenope

11 Parthenope is a large, bright asteroid located in the main asteroid belt.

History

Parthenope was discovered by Annibale de Gasparis on 11 May 1850, the second of his nine asteroid discoveries. It was named after Parthenopē, one of the Sirens in Greek mythology, said to have founded the city of Naples. De Gasparis "used his utmost endeavours to realise a 'Parthenope' in the heavens, such being the name suggested by Sir John Herschel on the occasion of the discovery of Hygiea in 1849". Two symbols were proposed for Parthenope: a fish and a star while such symbols were still in use, and later a lyre in lists of symbols. Both are obsolete.
In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.

Orbit

Parthenope orbits the Sun at an average distance of 2.454 astronomical units, with an orbital period of 3.845 years. Its distance from the Sun varies from 2.209 AU at its perihelion to 2.699 AU at its aphelion, indicated by its orbital eccentricity of 0.0998. Its orbit is inclined by 4.633° with respect to the ecliptic plane. It is classified as a background asteroid, as it does not belong to any known asteroid family.

Physical Characteristics

In 2007, Baer and Chesley calculated a higher mass and density for Parthenope based on perturbations by the 90 km asteroid 17 Thetis. Baer and Chesley calculated a mass of 6.3 kg with a density of 3.3 g/cm³. 2008 estimates by Baer suggest a mass of 6.15 kg. The 1997 and 2001 estimates by Viateau and Rapaport were closer to 5 kg with a density of 2.7 g/cm³.
Based upon a light curve that was generated from photometric observations of Parthenope at Pulkovo Observatory, it has a rotation period of 13.722 ± 0.001 hours and varies in brightness by 0.10 ± 0.0s in magnitude. The light curve displays three maxima and minima per cycle.