6223 Dahl
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 Track of Dahl next to NGC 772 with two supernovae | |
| Discovery[1] | |
|---|---|
| Discovered by | A. Mrkos |
| Discovery site | Kleť Obs. |
| Discovery date | 3 September 1980 |
| Designations | |
| (6223) Dahl | |
Named after | Roald Dahl (Welsh author)[2] |
| 1980 RD1 · 1949 XC 1972 YS · 1976 UV3 1982 BH9 · 1991 AK3 | |
| main-belt · (middle) | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 67.02 yr (24,479 days) |
| Aphelion | 3.0674 AU |
| Perihelion | 2.4039 AU |
| 2.7356 AU | |
| Eccentricity | 0.1213 |
| 4.52 yr (1,653 days) | |
| 38.698° | |
| 0° 13m 4.08s / day | |
| Inclination | 3.8564° |
| 294.31° | |
| 76.334° | |
| Physical characteristics | |
| Dimensions | 16.81 km (calculated)[3] 19.634±0.326 km[4][5] |
| 3.33±0.01 h[6] | |
| 0.033±0.004[5] 0.0335±0.0040[4] 0.057 (assumed)[3] | |
| C[3] | |
| 12.6[1][3][4] | |
6223 Dahl, provisional designation 1980 RD1, is a carbonaceous asteroid from the central region of the asteroid belt, approximately 18 kilometres in diameter. It was discovered on 3 September 1980, by Czech astronomer Antonín Mrkos at Kleť Observatory near České Budějovice in the Czech Republic.[7] The asteroid was named after author of children's books, Roald Dahl.[2]
Dahl orbits the Sun in the central main-belt at a distance of 2.4–3.1 AU once every 4 years and 6 months (1,653 days). Its orbit has an eccentricity of 0.12 and an inclination of 4° with respect to the ecliptic.[1] The first precovery was taken at the US Goethe Link Observatory in 1949, extending the asteroid's observation arc by 31 years prior to its discovery.[7]
Physical characteristics
Dahl has been characterised as a dark, carbonaceous C-type asteroid.[3]
Lightcurves
In November 2011, a rotational lightcurve of Dahl was obtained by Brett Waller at the Cedar Green Observatory in Virginia in the United States. It gave a rotation period of 3.33±0.01 hours with a brightness variation of 0.43 in magnitude (U=2).[6]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Dahl measures 19.6 kilometres in diameter and its surface has a low albedo of 0.034,[4] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 16.8 kilometres, as the higher the albedo (reflectivity), the lower a body's diameter for certain absolute magnitude.[3]
