(2153) Akiyama Main-belt Asteroid
Discovered on 1 December 1978 by Harvard Observatory at Harvard.
Named in memory of Kaoru Akiyama (1901-1970), professor at Hosei Univer sity, Tokyo, during 1930-1940 and 1949-1970, well known for his work on minor planets. Initially in collaboration with K. Hirayama, he made the first de tailed study of the orbit of the 3/2 commensurability object (153) Hilda. Name proposed by K. Tomita.Naming citation (MPC 5014), IAU / Minor Planet Center, via NASA/JPL
Where Akiyama is today
Seen from above the solar system on 2026-10-14: Akiyama is 3.05 au from the Sun and 2.21 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 2153 |
| Provisional designation | 1978 XD |
| Orbit class | Main-belt Asteroid |
| Diameter | 23.2 km (#1,839 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0570 |
| Rotation period | 12.5 hours |
| Absolute magnitude (H) | 12.13 |
| Orbital period | 5.52 years |
| Semi-major axis | 3.12 au |
| Perihelion – aphelion | 2.65 – 3.60 au |
| Eccentricity | 0.152 |
| Inclination | 1.17° |
| Closest distance between its orbit and Earth's (MOID) | 1.67 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.