(818) Kapteynia Main-belt Asteroid
Discovered on 21 February 1916 by M. F. Wolf at Heidelberg.
Where Kapteynia is today
Seen from above the solar system on 2026-10-14: Kapteynia is 2.93 au from the Sun and 2.51 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 818 |
| Provisional designation | A916 DF |
| Orbit class | Main-belt Asteroid |
| Diameter | 64.3 km (#535 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.100 |
| Rotation period | 16.4 hours |
| Absolute magnitude (H) | 9.24 |
| Orbital period | 5.65 years |
| Semi-major axis | 3.17 au |
| Perihelion – aphelion | 2.89 – 3.46 au |
| Eccentricity | 0.0893 |
| Inclination | 15.6° |
| Closest distance between its orbit and Earth's (MOID) | 1.93 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.