1293 Sonja
1293 Sonja, provisional designation, is a stony asteroid and bright Mars-crosser from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 26 September 1933, by Belgian astronomer Eugène Delporte at Uccle Observatory in Belgium. Two nights later, Sonja was independently discovered by Soviet astronomer Grigory Neujmin at Simeiz on the Crimean peninsula. The origin of the asteroid's name is unknown.
Orbit and classification
In the SMASS taxonomy, Sonja is classified as a Sq-type, an intermediary between the abundant S and rather rare Q-type asteroids. It orbits the Sun in the inner main-belt at a distance of 1.6–2.8 AU once every 3 years and 4 months. Its orbit has an eccentricity of 0.28 and an inclination of 5° with respect to the ecliptic. Sonjas observation arc begins with its official discovery observation at Uccle, as no precoveries were taken and no prior identifications were made.Physical characteristics
Rotation period
Several well-defined rotational lightcurves of Sonja were obtained from photometric observations during 2003–2016. Light-curve analysis gave a concurring rotation period of 2.876–2.879 hours with a brightness variation between 0.14 and 0.21 magnitude.In 2006, the first lightcurve was obtained by David Higgins, followed by Federico Manzini and Vladimir Benishek. Photometric observations continued in August 2008, by Petr Pravec at Ondřejov Observatory, and in 2016, four more lightcurves were obtained by Peter Kušnirák and Petr Pravec, as well as by Robert Stephens, Daniel Klinglesmith and Isaac Aznar.