1929 Kollaa, provisional designation 1939 BS, is a stony Vestian asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland, on 20 January 1939.[9] The asteroid was named after the Kollaa River in what is now Russia.[2]
Orbit and classification
Kollaa is a member of the Vesta family. Vestian asteroids have a composition akin to cumulate eucrite meteorites and are thought to have originated deep within 4 Vesta's crust, possibly from the Rheasilvia crater, a large impact crater on its southern hemisphere near the South pole, formed as a result of a subcatastrophic collision. The asteroid Vesta is the main-belt's second-most-massive body after 1 Ceres.[10]
The asteroid orbits the Sun in the inner main-belt at a distance of 2.2–2.5 AU once every 3 years and 8 months (1,327 days). Its orbit has an eccentricity of 0.07 and an inclination of 8° with respect to the ecliptic.[1] As no precoveries were taken, the asteroid's observation arc begins with its discovery.[9]
It has a well-defined rotation period of 2.98 hours, derived from two rotational lightcurve analysis. In March 2004, photometric observations at the U.S. Magdalena Ridge Observatory in New Mexico rendered a period of 2.980 hours with a brightness variation of 0.20 in magnitude (U=3).[a] In 2008 a second, concurring period was obtained by French amateur astronomer Pierre Antonini at his private Observatoire de Bédoin in France (132). It gave a period of 2.9887 hours and an amplitude 0.22 in magnitude (U=3).[7]
Diameter and albedo
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, the body measures 6.7 and 7.7 kilometers in diameter, respectively, and its surface has an albedo 0.39.[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.40 and calculates a diameter of 6.4 kilometers with an absolute magnitude of 12.7.[3]