(9691) Zwaan Main-belt Asteroid
Discovered on 24 September 1960 by van Houten, C. J., van Houten-Groeneveld, I., Gehrels, T. at Palomar.
Cornelis Zwaan (1928-1999), professor of astrophysics at Utrecht University, was a recognized authority on solar and stellar magnetism. Just before his death he finished a book (with C. J. Schrijver) on stellar magnetic fields. The name was suggested by C. de Jager.Naming citation (20001111/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Zwaan is today
Seen from above the solar system on 2026-10-14: Zwaan is 2.51 au from the Sun and 3.50 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9691 |
| Provisional designation | 6053 P-L |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.57 km (#8,164 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0540 |
| Absolute magnitude (H) | 14.67 |
| Orbital period | 4.21 years |
| Semi-major axis | 2.61 au |
| Perihelion – aphelion | 2.09 – 3.13 au |
| Eccentricity | 0.200 |
| Inclination | 3.32° |
| Closest distance between its orbit and Earth's (MOID) | 1.07 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Cornelis
All asteroids named after someone called Cornelis
Also discovered on 24 September 1960
- (1743) Schmidt
- (1744) Harriet
- (1776) Kuiper
- (1777) Gehrels
- (1795) Woltjer
- (1808) Bellerophon
- (1809) Prometheus
- (1810) Epimetheus
- (1811) Bruwer
- (1812) Gilgamesh
- (1846) Bengt
- (1868) Thersites