Discovered by K. Reinmuth Discovered 13 January 1929 Orbits Sun Asteroid group Asteroid belt | Discovery date 13 January 1929 Minor planet category main-belt · (outer) Absolute magnitude 10.8 Discoverer Karl Wilhelm Reinmuth | |
Alternative names 1929 AE · 1951 CA21951 CP · 1952 KE1964 PJ · 1973 AA4 Discovery site Landessternwarte Heidelberg-Königstuhl Similar 1862 Apollo, Sun, 1419 Danzig, 1056 Azalea, 1635 Bohrmann | ||
1985 Hopmann, provisional designation 1929 AE, is a carbonaceous asteroid in the outer regions of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 13 January 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.
The dark C-type asteroid orbits the Sun at a distance of 2.6–3.6 AU once every 5 years and 6 months (2,014 days). Its orbit has an eccentricity of 0.15 and an inclination of 17° with respect to the ecliptic. The first observation used for the body's observation arc was taken at the discovering observatory on 4 February 1926, or 22 days after its official discovering observation.
According to the survey carried out by the Infrared Astronomical Satellite IRAS, the asteroid measures 35.51 kilometers in diameter. The Collaborative Asteroid Lightcurve Link agrees with the Supplemental IRAS Minor Planet Survey (SIMPS) data and derives an albedo of 0.039 and a diameter of 35.47 kilometers, while observations with NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission gave an albedo of 0.06 and a diameter of 44.33 kilometers.
In January and February 2012, three rotational light-curves were obtained by Robert D. Stephens at Santana Observatory (646), California, Josep Maria Aymami at Carmelita Observatory (B20), Barcelona, and Patricia Moravec at Oakley Southern Sky Observatory (E09), Australia. The light-curves gave a well-defined rotation period of 17.476, 17.478 and 17.480 hours, respectively, with a brightness variation between 0.36 and 0.44 magnitude (U=3/3/3-). In 2016, a re-modeled light-curve, constructed from data compiled in the Lowell Photometric Database, also gave a concurring period.
The minor planet was named in memory of German astronomer Josef Hopmann (1890–1975), a director of Vienna Observatory between 1951 and 1962, a productive observer of variable and binary stars, and a participant in the international program to observe near-Earth asteroid 433 Eros in the early 1930s. The lunar crater Hopmann is also named in his honour. Naming citation was published before November 1977 (M.P.C. 4237).