3494 Purple Mountain
3494 Purple Mountain, provisional designation, is a bright Vestian asteroid and a formerly lost minor planet from the inner regions of the asteroid belt, approximately in diameter. First observed in 1962, it was officially discovered on 7 December 1980, by Chinese astronomers at the Purple Mountain Observatory in Nanking, China, and later named in honor of the discovering observatory. The V-type asteroid has a rotation period of 5.9 hours.
Orbit and classification
Purple Mountain is a core member of the Vesta family, a giant asteroid family of typically bright V-type asteroids. Vestian asteroids have a composition akin to cumulate eucrites and are thought to have originated deep within 4 Vesta's crust, possibly from the Rheasilvia crater, a large impact crater on its southern hemisphere near the South pole, formed as a result of a subcatastrophic collision. Vesta is the main belt's second-largest and second-most-massive body after. Based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the Flora family, a giant asteroid family and the largest family of stony asteroids in the main-belt.Purple Mountain orbits the Sun in the inner asteroid belt at a distance of 2.0–2.7 AU once every 3 years and 7 months. Its orbit has an eccentricity of 0.13 and an inclination of 6° with respect to the ecliptic. The body's observation arc begins with a precovery taken at Palomar Observatory in December 1951, or 29 years prior to its official discovery observation.
Lost asteroid
Purple Mountain has been a lost minor planet. In November 1962, Purple Mountain was observed as at Goethe Link Observatory. A total of three additional observations were taken at Crimea–Nauchnij in 1969 and 1972, when it was designated as and, respectively, but was subsequently lost with no follow-up observations until its official discovery at Nanking in 1980.Physical characteristics
Based on the Moving Object Catalog of the Sloan Digital Sky Survey, Purple Mountain is a common, stony S-type asteroid, with a sequential best-type taxonomy of SV. The Collaborative Asteroid Lightcurve Link also assumes it to be a stony S-type.In the SMASS-I classification by Xu, the asteroid is a V-type. This agrees with its measured high albedo often seen among the core members of the Vesta family. In 2013, a spectroscopic analysis showed it to have a composition very similar to the cumulate eucrite meteorites, which also suggests that the basaltic asteroid has originated from the crust of 4 Vesta.