.png) Lightcurve-based 3D-model of Aisleen | |
| Discovery[1] | |
|---|---|
| Discovered by | E. L. Johnson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 21 August 1946 |
| Designations | |
| (1568) Aisleen | |
Named after | Aisleen Johnson (discoverer's wife)[2] |
| 1946 QB | |
| main-belt · Phocaea[3][4][5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 70.70 yr (25,824 days) |
| Aphelion | 2.9502AU |
| Perihelion | 1.7557 AU |
| 2.3529 AU | |
| Eccentricity | 0.2538 |
| 3.61yr (1,318 days) | |
| 221.76° | |
| 0° 16m 23.16s / day | |
| Inclination | 24.867° |
| 146.18° | |
| 229.03° | |
| Physical characteristics | |
| Dimensions | 11.983±0.072 km[6] 12.448±0.084 km[7] 12.49±2.52 km[8] 12.67 km(calculated)[3] 14.04±0.96 km[9] |
| 6.67597±0.00005 h[10] 6.68±0.02h[11] 6.683±0.005 h[12] | |
| 0.130±0.019[9] 0.165±0.028[7] 0.1793±0.0322[6] 0.21±0.06[8] 0.23(assumed)[3] | |
| S[3] | |
| 11.57±0.21[13] · 11.7[1][3] · 12.1[6][9] · 12.14[8] · | |
1568 Aisleen (provisional designation1946 QB) is a stony Phocaeaasteroid from the inner regions of theasteroid belt, approximately 12.5 kilometers in diameter. It was discovered on 21 August 1946, by South African astronomerErnest Johnson atJohannesburg Observatory in South Africa.[14] It is named for the discoverer's wife, Aisleen Johnson.[2]
TheS-type asteroid is a member of thePhocaea family (701), a group of asteroids with similar orbital characteristics.[4][5] It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 7 months (1,318 days). Its orbit has aneccentricity of 0.25 and aninclination of 25° with respect to theecliptic.[1] As noprecoveries were taken, and no prior identifications were made, Aisleen'sobservation arc begins with its official discovery observation at Johannesburg.[14]
In August 2000, a rotationallightcurve of Aisleen was obtained from photometric observations made by Glen Malcolm at the Roach Motel Observatory (856) in California. The analysis gave a well-definedrotation period of 6.68 hours during which the brightness varied by 0.56 inmagnitude (U=3).[11] In April 2014, photometric observations byBrian D. Warner gave a period of 6.683 hours with an amplitude of 0.31 magnitude (U=3).[12] A modeled lightcurve from various data sources gave a concurring period of 6.67597 hours[10] and found apole of (109°,−68°).[12]
According to the surveys carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, Aisleen measures between 11.98 and 14.04 kilometers in diameter, and its surface has analbedo between 0.130 and 0.21.[6][7][8][9] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for Phocaea asteroids of 0.23 – derived from25 Phocaea, the family's most massiv member and namesake – and calculates a diameter of 12.67 kilometers based on anabsolute magnitude of 11.7.[3]
Thisminor planet was named by the discoverer for his wife, Aisleen Johnson.[2] The officialnaming citation was published by theMinor Planet Center on 31 January 1962 (M.P.C. 2116).[15]
