Discovery date 1 December 1978 Minor planet category main-belt · Themis Orbital period 2,016 days Orbits Sun Asteroid group Asteroid belt | MPC designation 2153 Akiyama Observation arc 62.27 yr (22,743 days) Discovered 1 December 1978 Asteroid family Themis family | |
Named after Kaoru Akiyama
(Japanese astronomer) Alternative names 1978 XD · 1955 UQ1
1972 YA · 1973 AK3
1977 VW · 1979 FS Discoverer Harvard College Observatory Discovery site Harvard College Observatory, Oak Ridge Observatory | ||
2153 Akiyama, provisional designation 1978 XD, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 17 kilometers in diameter. It was discovered by staff members at the Agassiz Station of the Harvard College Observatory on 1 December 1978.
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 2.6–3.6 AU once every 5 years and 6 months (2,017 days). Its orbit has an eccentricity of 0.15 and an inclination of 1° with respect to the ecliptic. The first precovery was taken at Palomar Observatory in 1954, extending the asteroid's observation arc by 24 years prior to its discovery.
According to the space-based surveys carried out by the Infrared Astronomical Satellite IRAS and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures 16.8 and 21.2 kilometers in diameter, respectively, with a corresponding albedo of 0.11 and 0.07. The Collaborative Asteroid Lightcurve Link assumes an intermediary albedo of 0.08 and calculates a diameter of 15.4 kilometers, based on an absolute magnitude of 12.42. Two rotational light-curves of this asteroid were obtained from photometric observations made at the U.S. Palomar Transient Factory in October 2010 and January 2012. They showed a rotation period of 7001125325000000000♠12.5325±0.0053 and 7001125132000000000♠12.5132±0.0053 hours with a brightness variation of 0.26 and 0.27 in magnitude, respectively (U=2/2).
The minor planet was named in memory of Kaoru Akiyama (1901–1970), professor at Hosei University, Tokyo, and widely known for his studies on minor planets. In collaboration with astronomer Kiyotsugu Hirayama, after whom the asteroid 1999 Hirayama is named, he made the first detailed orbital analysis of the asteroid 153 Hilda, which has a 2:3 orbital resonance with Jupiter. Naming citation was published on 1 November 1979 (M.P.C. 5014).