2058 Róka, provisional designation 1938 BH, is a Themistian asteroid from the outer regions of the asteroid belt, approximately 22 kilometers in diameter.
Róka is a member of the Themis family, a dynamical family of carbonaceous outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.7–3.6 AU once every 5 years and 6 months (2,016 days). Its orbit has an eccentricity of 0.15 and an inclination of 3° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Konkoly in 1938.[11]
In March 2005, a rotational lightcurve of Róka was obtained from photometric observations by French amateur astronomer René Roy. Lightcurve analysis gave a rotation period of 10.04 hours with a brightness variation of 0.34 magnitude (U=3-).[8] One month later, astronomer at the Rose-Hulman Observatory obtained another lightcurve with a concurring period of 10.09 hours and an amplitude of 0.40 magnitude (U=2).[9]
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Róka measures between 21.36 and 24.273 kilometers in diameter and its surface has an albedo between 0.1196 and 0.1542.[4][5][6][7] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0995 and calculates a diameter of 21.12 kilometers based on an absolute magnitude of 11.5.[3]
Naming
This minor planet was named in memory of Gedeon Róka (1906–1974), a Hungarian science writer and popularizer of astronomy from Budapest.[2] The approved naming citation was published by the Minor Planet Center on 1 February 1980 (M.P.C. 5183).[12]