| Discovery [1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 15 May 1985 |
| Designations | |
| (9298) Geake | |
Named after | John E. Geake (British astronomer)[2] |
| 1985 JM · 1994 VN2 | |
| main-belt · (middle) [3] Mitidika [4] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 60.89 yr (22,241 days) |
| Aphelion | 3.3406AU |
| Perihelion | 1.8041 AU |
| 2.5724 AU | |
| Eccentricity | 0.2987 |
| 4.13yr (1,507 days) | |
| 240.52° | |
| 0° 14m 20.04s / day | |
| Inclination | 12.113° |
| 211.83° | |
| 120.10° | |
| Physical characteristics | |
| Dimensions | 6.50 km(calculated)[3] 11.54±0.27 km[5] 11.73±3.10 km[6] 12.40±4.66 km[7] 12.68±4.23 km[8] 14.040±0.983 km[9][10] |
| 38.29±0.02h[11][a] | |
| 0.033±0.008[9][10] 0.049±0.002[5] 0.05±0.02[6] 0.050±0.026[8] 0.05±0.06[7] 0.20(assumed)[3] | |
| S(assumed)[3] | |
| 13.20[6] · 13.3[1][3] · 13.36[8] · 13.42[7] · 13.59±1.39[12] · 13.6[5][9] | |
9298 Geake, provisional designation1985 JM, is a Mitidikaasteroid from the central regions of theasteroid belt, approximately 12 kilometers in diameter. It was discovered on 15 May 1985, by American astronomerEdward Bowell at Lowell Observatory'sAnderson Mesa Station near Flagstaff, Arizona, United States.[13] The asteroid was named for British astronomerJohn E. Geake.[2]
Geake has been identified as a member of theMitidika family, a dispersedasteroid family of carbonaceousC-type asteroids. The family is named after2262 Mitidika (diameter of 9 km) and consists of 653 known members, the largest ones being404 Arsinoë (95 km) and5079 Brubeck (17 km).[4][14]: 23 [b]
The asteroid orbits the Sun in thecentral main-belt at a distance of 1.8–3.3 AU once every 4 years and 2 months (1,507 days). Its orbit has aneccentricity of 0.30 and aninclination of 12° with respect to theecliptic.[1] It was first observed on aprecovery taken atPalomar Observatory in May 1956, extending the body'sobservation arc by 29 years prior to its official discovery observation at Anderson Mesa.[13]
In August 2006, a rotationallightcurve ofGeake was obtained from photometric observations by American astronomerBrian Warner at his Palmer Divide Observatory (716) in Colorado. Lightcurve analysis gave arotation period of 38.29 hours with a brightness variation of 0.78magnitude (U=2).[11][a] While not being aslow rotator, it has a longer than average rotation, which lies normally between 2 and 20 hours. The body's high brightness amplitude of 0.78 magnitude also indicates that it has a non-spheroidal shape.
According to the surveys carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Geake measures between 11.54 and 14.040 kilometers in diameter and its surface has a lowalbedo between 0.033 and 0.05.[5][6][7][8][9][10]
Contrary to the results obtained by the space-based observatories, theCollaborative Asteroid Lightcurve Link assumes a standard albedo forstony asteroids of 0.20, derived from the family's namesake,[b] and consequently calculates a much shorter diameter of 6.50 kilometers based on anabsolute magnitude of 13.3, as the higher a body's reflectivity the smaller its diameter for a given brightness.[3]
Thisminor planet was named after British astronomerJohn E. Geake (1925–1998), who invented the direct-reading linearrefractometer, which was used by theCassini–Huygens space probe.[2] The official naming citation was published by theMinor Planet Center on 26 July 2000 (M.P.C. 41029).[15]
