(8639) Vonsovsky Main-belt Asteroid
Discovered on 3 November 1986 by A. Mrkos at Klet.
Břetislav Vonšovský (1937–2019) was the chairman of South Bohemian branch of the Czech Astronomical Society. He led Tábor Observatory as an enthusiastic popularizer of astronomy for 41 years. He dealt with lectures for schools and general public and was interested in stellar occultations.Naming citation (WGSBN Bull. 3, #1, 6), IAU / Minor Planet Center, via NASA/JPL
Where Vonsovsky is today
Seen from above the solar system on 2026-10-14: Vonsovsky is 1.92 au from the Sun and 1.12 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 8639 |
| Provisional designation | 1986 VB1 |
| Orbit class | Main-belt Asteroid |
| Rotation period | 4.63 hours |
| Absolute magnitude (H) | 14.93 |
| Orbital period | 3.33 years |
| Semi-major axis | 2.23 au |
| Perihelion – aphelion | 1.92 – 2.54 au |
| Eccentricity | 0.138 |
| Inclination | 5.13° |
| Closest distance between its orbit and Earth's (MOID) | 0.933 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.