2197 Shanghai

2197 Shanghai, provisional designation 1965 YN, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 22 kilometers in diameter. It was discovered on 30 December 1965, by astronomers at the Purple Mountain Observatory in Nanking, China.

The dark C-type asteroid is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.8–3.5 AU once every 5 years and 7 months (2,045 days). Its orbit has an eccentricity of 0.12 and an inclination of 2° with respect to the ecliptic.

In December 2010, a rotational light-curve was obtained for this asteroid from photometric observations taken at the U.S. Palomar Transient Factory in California. It gave a rotation period of 7000593840000000000♠5.9384±0.0023 hours with a brightness variation of 0.16 magnitude (U=2). A similar period of 7000599000000000000♠5.99±0.05 hours with an amplitude of 0.16 magnitude was derived by French amateur astronomer Pierre Antonini, observing the body one month later in January 2011 (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, the asteroid measures 20.2 and 23.9 kilometers in diameter and its surface has an albedo of 0.119 and 0.106, respectively. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0898 and a diameter of 22.2 kilometers, based on an absolute magnitude of 11.5.

The minor planet is named after Shanghai, the most populous city of China (pop. 24 million as of 2014). Located in the Yangtze River Delta in eastern China, it has the world's busiest container port. Naming citation was published on 1 June 1981 (M.P.C. 6059).