(8581) Johnen Main-belt Asteroid
Discovered on 28 December 1996 by N. Sato at Chichibu.
Named for a mountain in Nagano prefecture, part of the Japanese Northern Alps. Popular with climbers, the 2857-m peak is especially famous because an Englishman, Walter Weston (1861-1940), climbed it in 1894 and spread the word of its beauty all over the world.Naming citation (19981208/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Johnen is today
Seen from above the solar system on 2026-10-14: Johnen is 2.76 au from the Sun and 3.57 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 8581 |
| Provisional designation | 1996 YO2 |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.84 km (#9,165 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.248 |
| Absolute magnitude (H) | 13.6 |
| Orbital period | 4.78 years |
| Semi-major axis | 2.84 au |
| Perihelion – aphelion | 2.71 – 2.96 au |
| Eccentricity | 0.0439 |
| Inclination | 3.19° |
| Closest distance between its orbit and Earth's (MOID) | 1.73 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also discovered on 28 December 1996
More named asteroids discovered by N. Sato
- (7851) Azumino
- (8924) Iruma
- (8933) Kurobe
- (9230) Yasuda
- (10224) Hisashi
- (10880) Kaguya
- (10916) Okina-Ouna
- (12027) Masaakitanaka
- (12031) Kobaton
- (12456) Genichiaraki
- (12460) Mando
- (12469) Katsuura
← (8580) Pinsky · (8582) Kazuhisa →