Alternative names none Observation arc 60342 days (165.21 yr) Discovered 2 November 1850 Orbits Sun | Discovery date 2 November 1850 Minor planet category Main belt Orbital period 1,510 days Asteroid group Asteroid belt | |
 | ||
Pronunciation /ᵻˈdʒɪəriə/ i-JEER-ee-ə Discovery site Astronomical Observatory of Capodimonte Similar Annibale de Gasparis discoveries, Other celestial objects | ||
13 Egeria is a large main-belt G-type asteroid. It was discovered by A. de Gasparis on November 2, 1850. Egeria was named by Urbain Le Verrier, whose computations led to the discovery of Neptune, after the mythological nymph Egeria of Aricia, Italy, the wife of Numa Pompilius, second king of Rome.
Egeria occulted a star on January 8, 1992. Its disc was determined to be quite circular (217×196 km). On January 22, 2008, it occulted another star, and this occultation was timed by several observers in New Mexico and Arizona, coordinated by the IOTA Asteroid Occultation Program. The result showed that Egeria presented an approximately circular profile to Earth of 214.8×192 km, well in agreement with the 1992 occultation. It has also been studied by radar.
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. Spectral analysis of Egeria shows it to be unusually high in water content, 10.5–11.5% water by mass. This makes Egeria a prominent candidate for future water-mining ventures.