1218 Aster
Main-belt asteroid
From Wikipedia, the free encyclopedia
1218 Aster, provisional designation 1932 BJ, is a bright asteroid from the inner regions of the asteroid belt, approximately 5.5 kilometers in diameter. Discovered by Karl Reinmuth in 1932, it was later named after the flowering plant Aster.
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Shape model of Aster from its lightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 29 January 1932 |
| Designations | |
| (1218) Aster | |
| Pronunciation | /ËæstÉr/[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 | 2.5110 AU |
| Perihelion | 2.0158 AU |
| 2.2634 AU | |
| Eccentricity | 0.1094 |
| 3.41 yr (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] | |
Discovery
Aster was discovered on 29 January 1932, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.[5] Two nights later, it was independently discovered by Italian astronomer Mario A. Ferrero at the Pino Torinese Observatory at Turin, Italy.[3]
Classification and orbit
Aster orbits the Sun in the inner main-belt at a distance of 2.0â2.5 AU once every 3 years and 5 months (1,244 days). Its orbit has an eccentricity of 0.11 and an inclination of 3° with respect to the ecliptic.[1]
The asteroid's observation arc begins at the discovering observatory, one week after its official discovery observation.[5]
Physical characteristics
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Aster measures 5.554 kilometers in diameter and its surface has an albedo of 0.332.[4]
Lightcurves
As of 2017, rotational lightcurve of Aster has been obtained.[6] The body's rotation period, shape and variation in magnitude shifted from unknown movements[1][7] to specific identifiable spin/shape determinations.
Naming
The minor planet was named after the genus of flowers, Aster (also see List of minor planets named after animals and plants § Plants). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 113).[3]
