(8516) Hyakkai Main-belt Asteroid
Discovered on 13 October 1991 by Hioki, T., Hayakawa, S. at Okutama.
Masaaki Hyakkai (b. 1963) is a science teacher and president of Gunma Astronomical Society. As a volunteer lecturer at astronomical observation meetings, he works to popularize science and astronomy.Naming citation (20040107/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Hyakkai is today
Seen from above the solar system on 2026-10-14: Hyakkai is 3.11 au from the Sun and 3.82 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 8516 |
| Provisional designation | 1991 TW1 |
| Orbit class | Main-belt Asteroid |
| Rotation period | 4.80 hours |
| Spectral type | S |
| Absolute magnitude (H) | 13.41 |
| Orbital period | 4.57 years |
| Semi-major axis | 2.75 au |
| Perihelion – aphelion | 2.31 – 3.20 au |
| Eccentricity | 0.163 |
| Inclination | 5.86° |
| Closest distance between its orbit and Earth's (MOID) | 1.31 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Masaaki
All asteroids named after someone called Masaaki