(10304) Iwaki Main-belt Asteroid
Discovered on 30 September 1989 by Endate, K., Watanabe, K. at Kitami.
Masae Iwaki (b. 1933), an amateur astronomer in Oita, is the winner of the Vega Prize for distinguished women amateur astronomers. She has been very active in the popularization of astronomy through frequent star parties and lectures, as well as through writings in newspapers.Naming citation (20010509/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Iwaki is today
Seen from above the solar system on 2026-10-14: Iwaki is 1.96 au from the Sun and 0.986 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 10304 |
| Provisional designation | 1989 SY |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.62 km (#9,538 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.268 |
| Absolute magnitude (H) | 13.48 |
| Orbital period | 4.12 years |
| Semi-major axis | 2.57 au |
| Perihelion – aphelion | 1.85 – 3.29 au |
| Eccentricity | 0.280 |
| Inclination | 12.7° |
| Closest distance between its orbit and Earth's (MOID) | 0.884 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.