(9690) Houtgast Main-belt Asteroid
Discovered on 24 September 1960 by van Houten, C. J., van Houten-Groeneveld, I., Gehrels, T. at Palomar.
Dutch solar physicist Jacob Houtgast (1908-1982) was associate professor at University of Utrecht, known for his much-quoted 1942 paper on noncoherent scattering of light in Fraunhofer lines. Famous as a scientific eclipse observer, he chaired the IAU's subcommittee for solar eclipses.Naming citation (20001111/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Houtgast is today
Seen from above the solar system on 2026-10-14: Houtgast is 2.56 au from the Sun and 1.57 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9690 |
| Provisional designation | 6039 P-L |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.53 km (#8,220 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.239 |
| Absolute magnitude (H) | 12.88 |
| Orbital period | 4.70 years |
| Semi-major axis | 2.81 au |
| Perihelion – aphelion | 2.32 – 3.29 au |
| Eccentricity | 0.172 |
| Inclination | 9.23° |
| Closest distance between its orbit and Earth's (MOID) | 1.36 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Jacob
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- (12180) Kistemaker
- (12208) Jacobenglander
- (12645) Jacobrosales
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- (16120) Burnim
- (16165) Licht
- (19643) Jacobrucker
- (21926) Jacobperry
- (22730) Jacobhurwitz
- (23298) Loewenstein
- (23752) Jacobshapiro
All asteroids named after someone called Jacob
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