(21659) Fredholm Main-belt Asteroid
Discovered on 13 August 1999 by P. G. Comba at Prescott.
Ivar Fredholm (1866-1927) studied at the University of Uppsala and taught at the University of Stockholm. His main interest was in mathematical physics, and his fame rests on finding the general solution of the integral equation that now bears his name.Naming citation (20010509/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Fredholm is today
Seen from above the solar system on 2026-10-14: Fredholm is 2.82 au from the Sun and 3.72 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21659 |
| Provisional designation | 1999 PR3 |
| Orbit class | Main-belt Asteroid |
| Absolute magnitude (H) | 14.84 |
| Orbital period | 4.13 years |
| Semi-major axis | 2.57 au |
| Perihelion – aphelion | 2.20 – 2.95 au |
| Eccentricity | 0.147 |
| Inclination | 4.87° |
| Closest distance between its orbit and Earth's (MOID) | 1.19 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.