Discovered by Y. Väisälä MPC designation 1646 Rosseland Discovered 19 January 1939 Orbits Sun Discovery site Iso-Heikkilä Observatory | Discovery date 19 January 1939 Minor planet category main-belt · (inner) Absolute magnitude 11.82 Discoverer Yrjö Väisälä Asteroid group Asteroid belt | |
Named after Svein Rosseland
(astrophysicist) Alternative names 1939 BG · 1937 QH
1948 QR · 1955 NB
1977 FK · 1980 ME People also search for 1548 Palomaa, 1519 Kajaani | ||
1646 Rosseland, provisional designation 1939 BG, is a stony asteroid from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. It was discovered on 19 January 1939, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.
The S-type asteroid orbits the Sun at a distance of 2.1–2.6 AU once every 3 years and 8 months (1,324 days). Its orbit has an eccentricity of 0.12 and an inclination of 8° with respect to the ecliptic. Rosseland was first observed at Johannesburg Observatory as 1937 QH, extending the body's observation arc by 2 years prior to its official discovery observation in 1939.
American astronomer Richard P. Binzel obtained the first rotational light-curve of Rosseland in the early 1980s. It gave a rotation period of 69.2 hours with a brightness variation of 0.13 magnitude (U=2). During a survey of presumed slow rotators, photometric observations by Brazilian Cláudia Angeli and colleges gave a period of 69.2 hours and an amplitude of 0.45 magnitude (U=1).
According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Rosseland measures between 11.48 and 13.49 kilometers in diameter and its surface has an albedo between 0.18 and 0.2253. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 12.85 kilometers using an absolute magnitude of 11.82.
The minor planet is named in honor of renowned Norwegian Astrophysicist Svein Rosseland (1894–1985), founder and first director of the Institute for Theoretical Astrophysics in Oslo. His work on the theory of stellar interiors included studies of stellar rotation and stability and the derivation of the Rosseland mean opacity. The lunar crater Rosseland is also named after him. Naming citation was published before November 1977 (M.P.C. 3932).