Discovered by J. GibsonC. U. Cesco MPC designation 1919 Clemence Absolute magnitude 13.45 Asteroid group Asteroid belt | Discovery date 16 September 1971 Discovered 16 September 1971 Orbits Sun | |
Named after Gerald Clemence(astronomer) Alternative names 1971 SA · 1970 EA11971 QZ Discovery site Carlos U. Cesco Astronomical Station Discoverers Carlos Ulrrico Cesco, James B. Gibson People also search for Sun, 3833 Calingasta, 1920 Sarmiento | ||
1919 Clemence, provisional designation 1971 SA, is a bright Hungaria asteroid and suspected tumbler from the inner regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 16 September 1971, by American astronomer James Gibson together with Argentine astronomer Carlos Cesco at the Yale-Columbia Southern Station at Leoncito Astronomical Complex in Argentina.
The bright E-type asteroid, classified as a X-type body on the Tholen taxonomic scheme, is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.8–2.1 AU once every 2 years and 8 months (984 days). Its orbit has a typically low eccentricity of 0.09 and an inclination of 19° with respect to the ecliptic.
Photometric measurements of this body by American astronomer Brian Warner made in 2005 at the U.S. Palmer Divide Observatory (PDO), Colorado, showed a revised rotational light-curve with a period of 7001674000000000000♠67.4±0.1 hours and a brightness variation of 6999150000000000000♠0.15 in magnitude (U=2). Czech astronomer Petr Pravec from the Ondřejov Observatory believes this may be a tumbling asteroid, yet observations are not sufficient to determine a non-principal axis rotation.
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 3.2 kilometers in diameter and its surface has an outstandingly high albedo of 0.71, while the Collaborative Asteroid Lightcurve Link (CALL) assumes an albedo of 0.30 and calculates a somewhat larger diameter of 4.95 kilometers.
It is named for American astronomer Gerald Maurice Clemence (1908–1974), first scientific director of the United States Naval Observatory and professor of astronomy at the Yale Observatory, known for his work on the theory of the motion of Mars and Mercury, on the system of astronomical constants, and other research in celestial mechanics. He served as president of the American Astronomical Society and of IAU.