| Discovery[1] | |
|---|---|
| Discovery site | Perth Obs.(Bickley) |
| Discovery date | 13 June 1971 |
| Designations | |
| (1806) Derice | |
Named after | Derice Harwood (wife of astronomer)[2] |
| 1971 LC · 1927 EB 1942 TD · 1949 YD 1967 EB | |
| main-belt · Flora[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.44 yr (24,634 days) |
| Aphelion | 2.4750AU |
| Perihelion | 1.9990 AU |
| 2.2370 AU | |
| Eccentricity | 0.1064 |
| 3.35yr (1,222 days) | |
| 74.051° | |
| 0° 17m 40.56s / day | |
| Inclination | 3.8406° |
| 271.10° | |
| 193.78° | |
| Physical characteristics | |
| Dimensions | 7.976±0.759[4] 10.14±0.41 km[5] 10.697±0.061 km[6] 10.7 km(derived)[7] |
| 3.22352±0.00004h[a] 3.2236±0.0005 h[a] 3.2237±0.0001 h[a] 3.2240±0.0005 h[8] 3.4602±0.0007 h[9] | |
| 0.035±0.149[4] 0.2149[7] 0.2474±0.0669[6] 0.282±0.025[5] | |
| S[3] | |
| 11.65±0.06(R)[a] · 12.00[5][6] · 12.1[1] · 12.14±0.078[3][7] | |
1806 Derice, provisional designation1971 LC, is a stony Floraasteroid from the inner regions of theasteroid belt, approximately 10 kilometers in diameter. Discovered on 13 June 1971, at the Bickley site of thePerth Observatory in Western Australia, it was the first discovery of a minor planet ever made inOceania. The asteroid was named after the wife of Dennis Harwood, staff member at Bickley.[2][10]
TheS-type asteroid is a member of theFlora 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 aneccentricity of 0.11 and aninclination of 4° with respect to theecliptic.[1] The first usedprecovery was taken atPalomar Observatory in 1949, extending the asteroid'sobservation arc by 22 years prior to its official discovery at Bickley. The first unused observation dates back to 1927, at Tokyo Observatory.[10]
A large number of rotationallightcurves for this asteroid were obtained from several photometric observations. The first observations were made by Italian astronomerSilvano Casulli in November 2006, and gave arotation period3.4602±0.0007 hours with a brightness amplitude of 0.19 inmagnitude (U=3).[9]
One month later, in December 2006, observations at the Carbuncle Hill Observatory gave a period of3.2240±0.0005 hours with an identical amplitude of 0.19 in magnitude (U=3).[8]
Between November 2009 and December 2012, Czech astronomerPetr Pravec atOndřejov Observatory obtained three more lightcurves 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).[a]
According to the space-based surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, the asteroid measures between 8.0 and 10.7 kilometers in diameter, respectively, and its surface has analbedo between 0.035 and 0.282.[4][5][6] Astronomer Petr Pravec and theCollaborative Asteroid Lightcurve Link derive an albedo of 0.21 and a diameter of 10.7 kilometers with anabsolute magnitude of 12.4.[3][7]
Thisminor planet was named after Derice Harwood, wife of Dennis Harwood,astrometric staff member of the discovering Perth Observatory.[2] The official naming citation was published by theMinor Planet Center on 11 December 1981 (M.P.C. 6530).[11]
