9423 Abt, and after whom the minor planet 2234 Schmadel is named. The official naming citation was published by the Minor Planet Center on 1 June 1996 . 6805 Abstracta 6805 Abstracta, provisional designation , is a carbonaceous Themistian asteroid and slow rotator from the outer region of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 24 September 1960, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar Observatory in California, United States. The asteroid was named for the astronomical bibliography Astronomy and Astrophysics Abstracts. Orbit 	6805 Abstracta
6665503	9423 Abt 9423 Abt 9423 Abt, provisional designation ", is a stony background asteroid from the central region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 12 January 1996, by the Spacewatch project of the University of Arizona at Kitt Peak National Observatory, United States. The asteroid was named after American astronomer Helmut Abt. Orbit and classification. Abt" is a non-family asteroid from the main belt's background population. It orbits the Sun in the central main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,614 days). Its orbit has an  eccentricity of 0.10 and an inclination of 9° with respect to the ecliptic. It was first identified as at Crimea-Nauchnij in February 1974, extending the body's observation arc by 22 years prior to its official discovery observation at Kitt Peak. Naming. This minor planet was named after American astrophysicist Helmut Abt (born 1925), one of the founders of the discovering Kitt Peak National Observatory, after which the minor planet 2322 Kitt Peak is named. His research included stellar properties and systems. As senior editor of "The Astrophysical Journal" he was responsible for converting it into its digital  format. The official naming citation was published by the Minor Planet Center on 11 November 2000 . Physical characteristics. Rotation period. In 2006, a rotational lightcurve of "Abt" was obtained from photometric observation at Hunters Hill Observatory, Australia. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of 0.30 magnitude (). In 2012, a second lightcurve from the Palomar Transient Factory, California, gave a concurring period of hours with an amplitude of 0.33 magnitude (). Diameter and albedo. According to the surveys carried out by the NEOWISE mission of the NASA's Wide-field Infrared Survey Explorer and  the Japanese Akari satellite, "Abt" measures 12.690 and 12.84 kilometers in diameter, and its surface has an albedo of 0.132 and 0.141, respectively. The "Collaborative Asteroid Lightcurve Link" calculates a diameter of 13.29 kilometers, assuming an albedo of 0.10, a compromise figure between the brighter stony and darker carbonaceous bodies from the inner and outer asteroid-belt, respectively. 9423 Abt 9423 Abt, provisional designation "", is a stony background asteroid from the central region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 12 January 1996, by the Spacewatch project of the University of Arizona at Kitt