| Discovery[1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 21 September 1987 |
| Designations | |
| (5771) Somerville | |
Named after | Mary Somerville[2] (Scottishpolymath) |
| 1987 ST1 · 1982 YY1 1989 BG1 | |
| main-belt · (outer)[3] Lixiaohua[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 34.36 yr (12,549 days) |
| Aphelion | 3.8347AU |
| Perihelion | 2.4381 AU |
| 3.1364 AU | |
| Eccentricity | 0.2226 |
| 5.55yr (2,029 days) | |
| 135.29° | |
| 0° 10m 38.64s / day | |
| Inclination | 8.2191° |
| 288.45° | |
| 101.58° | |
| Physical characteristics | |
| Dimensions | 22.84 km(derived)[3] 24.90±6.97 km[5] 26.43±5.87 km[6] 28.306±0.264 km[7] 33.60±2.18 km[8] |
| 9.20±0.05h[9][a] | |
| 0.017±0.002[8] 0.029±0.001[7] 0.03±0.03[6] 0.04±0.08[5] 0.0407(derived)[3] | |
| C [3] | |
| 12.20[7] · 12.30[1][3][6] · 12.40[8] · 12.50[5] · 12.94±0.26[10] | |
5771 Somerville, provisional designation1987 ST1, is a carbonaceous Lixiaohuaasteroid from the outer regions of theasteroid belt, approximately 26 kilometers in diameter. It was discovered on 21 September 1987, by American astronomerEdward Bowell at theAnderson Mesa Station of theLowell Observatory in Flagstaff, Arizona.[11] The asteroid was named for Scottish polymathMary Somerville.[2]
Somerville is a member of theLixiaohua family,[4] an outer-beltasteroid family with more than 700 known members, consisting ofC-type andX-type asteroids. The family's namesake is3556 Lixiaohua.[12]: 23
The asteroid orbits the Sun in theouter main-belt at a distance of 2.4–3.8 AU once every 5 years and 7 months (2,029 days). Its orbit has aneccentricity of 0.22 and aninclination of 8° with respect to theecliptic.[1]Somerville was first identified as1982 YY1 atPurple Mountain Observatory in December 1982. The body'sobservation arc begins with its official discovery observation at Flagstaff.[11]
Somerville is an assumedC-type asteroid.[3]
In March 2012, a rotationallightcurve ofSomerville was obtained from photometric observations by American astronomerBrian Warner at his Palmer Divide Observatory (716) in Colorado. Lightcurve analysis gave arotation period of 9.20 hours with a brightness amplitude of 0.80magnitude (U=2+).[9][a]
According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Somerville measures between 24.90 and 33.60 kilometers in diameter and its surface has analbedo between 0.017 and 0.04.[5][6][7][8]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0407 and a diameter of 22.84 kilometers based on anabsolute magnitude of 12.3.[3]
Thisminor planet was named afterMary Somerville (1780–1872; née Fairfax), a Scottishpolymath andscience writer who studied mathematics and astronomy. She is considered to be one of Europe's most distinguished women scientists of her time.[2] The official naming citation was published by theMinor Planet Center on 12 July (M.P.C. 25444).[13]
