Discovery date 13 June 1971 Minor planet category main-belt · Flora Orbital period 1,224 days Orbits Sun Discovery site Perth Observatory Bickley Discoverer Perth Observatory | MPC designation 1806 Derice Observation arc 66.96 yr (24,457 days) Discovered 13 June 1971 Asteroid family Flora family Asteroid group Asteroid belt | |
Named after Derice Harwood
(wife of astronomer) Alternative names 1971 LC · 1927 EB
1942 TD · 1949 YD
1967 EB | ||
1806 Derice, provisional designation 1971 LC, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. Discovered on 13 June 1971, at the Bickley site of the Perth Observatory in Western Australia, it was the first discovery of a minor planet ever made in Oceania.
The S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,222 days). Its orbit has an eccentricity of 0.11 and an inclination of 4° with respect to the ecliptic. The first used precovery was taken at Palomar Observatory in 1949, extending the asteroid's observation arc by 22 years prior to its discovery. The first unused observations date back to 1927 at Tokyo Observatory.
A large number of rotational light-curves for this asteroid were obtained from several photometric observations. The first observations were made by Italian astronomer Silvano Casulli in November 2006, and gave a rotation period 7000346020000000000♠3.4602±0.0007 hours with a brightness amplitude of 0.19 in magnitude (U=3). One month later, in December 2006, observations at the Carbuncle Hill Observatory gave a period of 7000322400000000000♠3.2240±0.0005 hours with an identical amplitude of 0.19 in magnitude (U=3). Between November 2009 and December 2012, Czech astronomer Petr Pravec at Ondřejov Observatory obtained three more light-curves with periods between 3.2235 and 3.2237 hours and corresponding amplitudes of 0.07. 0.10 and 0.10, respectively (U=3/3/3).
According to the space-based surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures between 8.0 and 10.7 kilometers in diameter, respectively, and its surface has a albedo between 0.035 and 0.282. Astronomer Petr Pravec and the Collaborative Asteroid Lightcurve Link derive an albedo of 0.21 and a diameter of 10.7 kilometers, based on an absolute magnitude of 12.4.
The asteroid is named after Derice Harwood, wife of Dennis Harwood, astrometric staff member of the discovering Perth Observatory. Naming citation was published on 11 December 1981 (M.P.C. 6530).