(8633) Keisukenagao Main-belt Asteroid
Discovered on 16 March 1981 by S. J. Bus at Siding Spring.
Keisuke Nagao (b. 1949) is a professor at the Geochemical Research Center of the University of Tokyo. He specializes in the analysis of noble gas isotopes in meteorites and has interpreted the irradiation history of (25143) Itokawa using grains returned by the Hayabusa mission.Naming citation (MPC batch dated 2014-07-12), IAU / Minor Planet Center, via NASA/JPL
Where Keisukenagao is today
Seen from above the solar system on 2026-10-14: Keisukenagao is 3.26 au from the Sun and 4.01 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 8633 |
| Provisional designation | 1981 FC1 |
| Orbit class | Main-belt Asteroid |
| Diameter | 7.60 km (#7,009 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.193 |
| Rotation period | 4.86 hours |
| Absolute magnitude (H) | 13.26 |
| Orbital period | 5.60 years |
| Semi-major axis | 3.15 au |
| Perihelion – aphelion | 2.64 – 3.66 au |
| Eccentricity | 0.162 |
| Inclination | 8.85° |
| Closest distance between its orbit and Earth's (MOID) | 1.66 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.