Discovered by A. Kopff MPC designation 3133 Sendai Minor planet category main-belt · Flora Orbits Sun Asteroid family Flora family | Discovery date 4 October 1907 Named after Sendai (Japanese city) Discovered 4 October 1907 Discoverer August Kopff Asteroid group Asteroid belt | |
Alternative names A907 TC · 1968 TO
1973 DN · 1981 UX
1984 QG1 · A907 XA Discovery site Heidelberg-Königstuhl State Observatory Similar Sun, 614 Pia, 596 Scheila, 617 Patroclus, 624 Hektor | ||
3133 Sendai, provisional designation A907 TC, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered by German astronomer August Kopff at Heidelberg Observatory, southern Germany, on 4 October 1907.
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 1.8–2.5 AU once every 3 years and 3 months (1,176 days). Its orbit has an eccentricity of 0.16 and an inclination of 7° with respect to the ecliptic.
According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its extended NEOWISE mission, the asteroid's surface has an albedo of 0.21 and 0.31, with a diameter of 8.3 and 7.3 kilometers, respectively. The Collaborative Asteroid Lightcurve Link assumes an intermediate albedo of 0.24 – which derives from 8 Flora, the largest member and namesake of this orbital family – and calculates a concurring diameter of 7.5 kilometers. In 2010, two rotational light-curves were obtained by amateur astronomer Ralph Megna at Goat Mountain Astronomical Research Station (G79), and by the U.S. Palomar Transient Factory in California. The concurring light-curves showed a rotation period of 7000577600000000000♠5.776±0.005 and 7000574910000000000♠5.7491±0.0008 hours, respectively (U=3-/2).
The minor planet is named for the second largest city north of Tokyo, Sendai (pop. 1 million), location of the Tōhoku University. It is the home of the Sendai Astronomical Observatory, which was founded in 1955, on appeal by the Sendai Amateur Astronomical Association. The observatory has discovered several minor planets. Naming citation was published on 29 September 1985 (M.P.C. 10045).