(9971) Ishihara Main-belt Asteroid
Discovered on 16 April 1993 by Endate, K., Watanabe, K. at Kitami.
Takahiro Ishihara (b. 1961) was president of the Hiroshima Astronomical Society from 1987 to 1997 and is currently the society's director responsible for spreading awareness of astronomy. Comet observations are his particular personal passion.Naming citation (20030106/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Ishihara is today
Seen from above the solar system on 2026-10-14: Ishihara is 2.24 au from the Sun and 1.25 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9971 |
| Provisional designation | 1993 HS |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.01 km (#10,597 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.233 |
| Rotation period | 6.71 hours |
| Absolute magnitude (H) | 13.97 |
| Orbital period | 3.22 years |
| Semi-major axis | 2.18 au |
| Perihelion – aphelion | 1.91 – 2.45 au |
| Eccentricity | 0.122 |
| Inclination | 2.74° |
| Closest distance between its orbit and Earth's (MOID) | 0.900 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Takahiro
All asteroids named after someone called Takahiro
Also discovered on 16 April 1993
- (6104) Takao
- (6200) Hachinohe
- (6201) Ichiroshimizu
- (6919) Tomonaga
- (9067) Katsuno
- (9375) Omodaka
- (10555) Tagaharue
- (13576) Gotoyoshi
- (13577) Ukawa
- (16624) Hoshizawa
- (21148) Billramsey