1457 Ankara
1457 Ankara, provisional designation, is a stony asteroid from the central region of the asteroid belt, approximately 18 kilometers in diameter. It was discovered on 3 August 1937, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany, and later named for the Turkish capital city of Ankara.
Orbit and classification
Ankara orbits the Sun in the middle of the main-belt at a distance of 2.3–3.1 AU once every 4 years and 5 months. Its orbit has an eccentricity of 0.15 and an inclination of 6° with respect to the ecliptic. It was first observed as at Uccle Observatory in 1933, extending the body's observation arc by 4 years prior to its official discovery observation at Heidelberg.Physical characteristics
Rotation period
A rotational lightcurve of Ankara was obtained from photometric observations by French amateur astronomer René Roy in September 2004. Lightcurve analysis gave a rotation period of 31.8 hours with a brightness variation of 0.21 magnitude. While not being a slow rotator, Ankaras spin rate is slower than that of most asteroids, which typically rotate within 20 hours once around their axis.Diameter and albedo
According to the surveys carried out by the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ankara measures between 17.834 and 19.82 kilometers in diameter and its surface has an albedo between 0.258 and 0.320.The Collaborative Asteroid Lightcurve Link assumes a lower albedo of 0.10 – a compromise value that lies between the albedos for stony and carbonaceous asteroids, chosen by CALL for all non-family asteroids with a semi-major axis between 2.6 and 2.7 AU – and consequently calculates a larger diameter of 29.08 kilometers with an absolute magnitude of 10.8, as a body's diameter and albedo are inversely related to each other.