Discovered by T. Seki MPC designation 2571 Geisei Orbital period 1,215 days Orbits Sun Asteroid family Flora family | Discovery date 23 October 1981 Minor planet category main-belt · Flora Discovered 23 October 1981 Discoverer Tsutomu Seki Discovery site Geisei Observatory | |
Named after Geisei
(village, observatory) Alternative names 1981 UC · 1931 TA4
1934 NV · 1944 OD
1961 XG · 1981 WR6
A911 UC Similar Sun, Asteroid belt, Solar System, Comet Ikeya–Seki, 8 Flora | ||
2571 Geisei, provisional designation 1981 UC, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by Japanese astronomer Tsutomu Seki at Geisei Observatory on 23 October 1981.
The S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,215 days). Its orbit has an eccentricity of 0.19 and an inclination of 3° with respect to the ecliptic. The first used precovery was taken at Lowell Observatory in 1931, extending the asteroid's observation arc by 50 years prior to its discovery, while the first unused observation at Heidelberg Observatory dates back to 1911.
A rotational light-curve for this asteroid was obtained from photometric observations made at the Australian Oakley Southern Sky Observatory (E09) in September 2014. The light-curve gave a rotation period of 7000782300000000000♠7.823±0.005 hours with a brightness variation of 0.50 in magnitude (U=3-).
According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, the asteroid measures 6.6 kilometers in diameter and its surface has an albedo of 0.257, while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of this orbital family – and calculates a diameter of 7.1 kilometers, based on an absolute magnitude of 12.9.
The minor planet is named after the small Japanese village of Geisei, where the discovering observatory is located. Geisei is situated near the city of Kōchi, after which Tsutomu Seki's first discovery, the asteroid 2396 Kochi, is named. Naming citation was published on 6 June 1982 (M.P.C. 6956).