_Aster.png) Shape model ofAster from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 29 January 1932 |
| Designations | |
| (1218) Aster | |
| Pronunciation | /ˈæstər/[2] |
Named after | Aster(genus of flowers)[3] |
| 1932 BJ · 1978 TJ5 1978 VQ12 | |
| main-belt · (inner) | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 85.35 yr (31,173 days) |
| Aphelion | 2.5110AU |
| Perihelion | 2.0158 AU |
| 2.2634 AU | |
| Eccentricity | 0.1094 |
| 3.41yr (1,244 days) | |
| 56.714° | |
| 0° 17m 21.84s / day | |
| Inclination | 3.1572° |
| 63.820° | |
| 69.372° | |
| Physical characteristics | |
| Dimensions | 5.554±0.084 km[4] |
| 0.332±0.043[4] | |
| 13.2[1] | |
1218 Aster, provisional designation1932 BJ, is a brightasteroid from the inner regions of theasteroid belt, approximately 5.5 kilometers in diameter. Discovered byKarl Reinmuth in 1932, it was later named after the flowering plantAster.
Aster was discovered on 29 January 1932, by German astronomerKarl Reinmuth atHeidelberg Observatory in southern Germany.[5] Two nights later, it was independently discovered by Italian astronomerMario A. Ferrero at thePino Torinese Observatory atTurin, Italy.[3]
Aster orbits the Sun in theinner main-belt at a distance of 2.0–2.5 AU once every 3 years and 5 months (1,244 days). Its orbit has aneccentricity of 0.11 and aninclination of 3° with respect to theecliptic.[1]
The asteroid'sobservation arc begins at the discovering observatory, one week after its official discovery observation.[5]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Aster measures 5.554 kilometers in diameter and its surface has analbedo of 0.332.[4]
As of 2017, rotationallightcurve ofAster has been obtained.[6] The body'srotation period, shape and variation inmagnitude shifted from unknown movements[1][7] to specific identifiable spin/shape determinations.
Theminor planet was named after the genus of flowers,Aster(also seeList of minor planets named after animals and plants § Plants). The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 113).[3]
