Discovered by Y. Väisälä MPC designation 1451 Grano Minor planet category main-belt · Flora Orbits Sun Asteroid family Flora family Asteroid group Asteroid belt | Discovery date 22 February 1938 Alternative names 1938 DT · 1976 WK Discovered 22 February 1938 Discoverer Yrjö Väisälä Discovery site Iso-Heikkilä Observatory | |
Named after Johannes Gabriel Granö
(University of Turku) Similar 1450 Raimonda, Sun, 8 Flora | ||
1451 Granö, provisional designation 1938 DT, is a stony Florian asteroid and slow rotator from the inner regions of the asteroid belt, approximately 6.5 kilometers in diameter. It was discovered on 22 February 1938, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.
The asteroid is a member of the Flora family, a large group of stony S-type asteroids in the main-belt. It orbits the Sun at a distance of 1.9–2.5 AU once every 3 years and 3 months (1,195 days). Its orbit has an eccentricity of 0.12 and an inclination of 5° with respect to the ecliptic. As no precoveries were taken, and no previous identifications were made, Granö's observation arc begins with its official discovery observation.
A rotational light-curve of Granö was obtained from photometric observations made by amateur astronomer Robert D. Stephens at GMARS and Santana Observatories in March 2010. It gave a long rotation period of 138 hours with a brightness variation of 0.65 magnitude (U=2+). The result supersedes a previous period of 5.1 hours from May 2007 (U=2-).
According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Granö measures between 6.17 and 9.70 kilometers in diameter, and its surface has an albedo between 0.171 and 0.429. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 6.81 kilometers using an absolute magnitude of 13.2.
This minor planet was named after J. G. Granö (1882−1956), Finnish professor of geography and rector at University of Turku from 1932 to 1934. Naming citation was published before November 1977 (M.P.C. 2277).