Discovered by L. Oterma MPC designation 1695 Walbeck Observation arc 75.07 yr (27,419 days) Orbits Sun Discovery site Iso-Heikkilä Observatory | Discovery date 15 October 1941 Minor planet category main-belt · (middle) Discovered 15 October 1941 Discoverer Liisi Oterma Asteroid group Asteroid belt | |
Alternative names 1941 UO · 1964 QA
1964 RE Named after Henrik Johan Walbeck (Geodesy) People also search for 1680 Per Brahe, Sun, 2268 Szmytowna | ||
1695 Walbeck, provisional designation 1941 UO, is a carbonaceous asteroid from the middle 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.
In the SMASS taxonomy, the C-type asteroid is classified as Cg-type, an intermediate to the G-type asteroids. The asteroid orbits the Sun 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. Walbeck's observation arc begins the night after its official discovery observation.
In November 2006, a rotational light-curve 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 (U=3). Two similar periods were obtained by David Romeuf and by a team of Hungarian astronomers (U=2/2).
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 its subsequent NEOWISE mission, Walbeck measures between 17.88 and 19.62 kilometers in diameter and its surface has an albedo between 0.037 and 0.051. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.046 and a diameter of 19.60 kilometers based on an absolute magnitude of 12.5.
The minor planet was named in memory of Finnish scientist Henrik Johan Walbeck (1793–1822), astronomer and geodesist at the old Academia Aboensis who used the method of least squares to derive a good value for the Earth's flattening. Naming citation was published on 1 April 1980 (M.P.C. 5281).