Discovered by K. Reinmuth MPC designation 1669 Dagmar Discovered 7 September 1934 Spectral type G-type asteroid Asteroid family Themis family | Discovery date 7 September 1934 Minor planet category main-belt · Themis Orbits Sun Discoverer Karl Wilhelm Reinmuth | |
Named after Generic name
(common German name) Alternative names 1934 RS · 1943 GE
1950 PX · 1953 AD
1957 WA · 1959 CV
1962 RH Discovery site Landessternwarte Heidelberg-Königstuhl Similar 1862 Apollo, Sun, 1419 Danzig, 1056 Azalea, 1111 Reinmuthia | ||
1669 Dagmar, provisional designation 1934 RS, is a rare-type Themistian asteroid from the outer region of the asteroid belt, approximately 42 kilometers in diameter. It was discovered on 7 September 1934, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.
The asteroid is a member of the Themis family, a large group of asteroids in the outer main-belt. It has a rare G-type spectra (or Cg-type in the SMASS taxonomy), similar to 1 Ceres, the largest asteroid and only dwarf planet in the asteroid belt. Dagmar orbits the Sun at a distance of 2.8–3.5 AU once every 5 years and 7 months (2,031 days). Its orbit has an eccentricity of 0.11 and an inclination of 1° with respect to the ecliptic. As no precoveries were taken, and no prior identifications were made, Dagmar's observation arc begins with its official discovery observation.
Astronomer Federico Manzini obtained a provisional light-curve of Dagmar from photometric observations in March 2004. It gave a tentative rotation period of 12 hours with a brightness variation of 0.15 magnitude (U=1). As of 2017, no secure period has yet been published.
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, Dagmar measures between 35.78 and 45.194 kilometers in diameter, and its surface has an albedo between 0.035 and 0.057. The Collaborative Asteroid Lightcurve Link adopts the results obtained by 17 observations made by IRAS, that is an albedo of 0.0565 and a diameter of 35.78 kilometers, using an absolute magnitude of 10.97.
This minor planet was named by the discoverer after a common German feminine name. No special meaning is assigned to this name. Naming citation was published before November 1977 (M.P.C. 2901).