11 Parthenope is a large, bright main-belt asteroid.
Parthenope was discovered by Annibale de Gasparis on May 11, 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".
There have been two observed Parthenopian occultations, on February 13, 1987, and April 28, 2006.
On August 6, 2008, during a perihelic opposition, Parthenope had an apparent magnitude of 8.8.
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.
Based upon a light curve that was generated from photometric observations of this asteroid 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. The JPL Small-Body Database lists a rotation period of 13.7204 hours.