_Ankara.png) Shape ofAnkara modelled from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 3 August 1937 |
| Designations | |
| (1457) Ankara | |
Named after | Ankara(Turkish capital)[2] |
| 1937 PA · 1933 SA 1934 XG · 1936 FL1 1943 YD · 1966 BG | |
| main-belt · (middle)[3] | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 82.95 yr (30,296 days) |
| Aphelion | 3.1134AU |
| Perihelion | 2.2802 AU |
| 2.6968 AU | |
| Eccentricity | 0.1545 |
| 4.43yr (1,618 days) | |
| 63.234° | |
| 0° 13m 21.36s / day | |
| Inclination | 6.0913° |
| 296.31° | |
| 296.31° | |
| Physical characteristics | |
| Dimensions | 17.834±0.207 km[4] 18.495±0.068 km[5] 18.95±0.63 km[6] 19.82±0.26 km[7] 29.08 km(calculated)[3] |
| 31.8±0.6h[8] | |
| 0.1(assumed)[3] 0.258±0.051[6] 0.262±0.008[7] 0.3038±0.0536[5] 0.320±0.037[4] | |
| S[3] | |
| 10.60[7][5] · 10.70[6] · 10.8[1][3] | |
1457 Ankara, provisional designation1937 PA, is a stonyasteroid from the central region of theasteroid belt, approximately 18 kilometers in diameter. It was discovered on 3 August 1937, by German astronomerKarl Reinmuth atHeidelberg Observatory in southwest Germany, and later named for the Turkish capital city ofAnkara.[2][9]
Ankara orbits the Sun in themiddle of the main-belt at a distance of 2.3–3.1 AU once every 4 years and 5 months (1,618 days). Its orbit has aneccentricity of 0.15 and aninclination of 6° with respect to theecliptic.[1] It was first observed as1933 SA atUccle Observatory in 1933, extending the body'sobservation arc by 4 years prior to its official discovery observation at Heidelberg.[9]
A rotationallightcurve ofAnkara was obtained from photometric observations by French amateur astronomerRené Roy in September 2004. Lightcurve analysis gave arotation period of 31.8 hours with a brightness variation of 0.21magnitude (U=2).[8] While not being aslow rotator,Ankara's spin rate is slower than that of most asteroids, which typically rotate within 20 hours once around their axis.
According to the surveys carried out by the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Ankara measures between 17.834 and 19.82 kilometers in diameter and its surface has analbedo between 0.258 and 0.320.[4][5][6][7]
TheCollaborative Asteroid Lightcurve Link (CALL) assumes a lower albedo of 0.10 – a compromise value that lies between the albedos forstony (0.20) andcarbonaceous (0.057) asteroids, chosen by CALL for all non-family asteroids with asemi-major axis between 2.6 and 2.7 AU – and consequently calculates a larger diameter of 29.08 kilometers with anabsolute magnitude of 10.8, as a body's diameter and albedo are inversely related to each other.[3]
Thisminor planet was named after the Turkish capitalAnkara. The official naming citation was proposed by Wolfgang Gleißberg, a German Solar astronomer, who immigrated to Turkey, after he was dismissed at the Breslau Observatory in Nazi Germany in 1933, because he had a Jewish grandfather. The citation was first mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H131).[2][10]
