1695 Walbeck
1695 Walbeck, provisional designation , is a carbonaceous asteroid from the central region of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 15 October 1941, by Finnish astronomer Liisi Oterma at Turku Observatory in Southwest Finland, and named after Henrik Walbeck. Classification and orbit The asteroid orbits the Sun in the central main-belt at a distance of 2.0–3.6 AU once every 4 years and 8 months (1,694 days). Its orbit has an eccentricity of 0.29 and an inclination of 17° with respect to the ecliptic. Walbecks observation arc begins the night after its official discovery observation. Physical characteristics In the SMASS taxonomy, the carbonaceous asteroid is characterized as a Cg-type, an intermediate between the C-type and G-type asteroids. Lightcurves In November 2006, a rotational lightcurve of Walbeck was obtained from photometric observations by French amateur astronomer Pierre Antonini. It gave a rotation period of 5.1607 hours with a brightness variation of 0.22 magnitude (). Two similar periods were obtained by David Romeuf and by a team of Hungarian astronomers (). Diameter and albedo According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with