(4001) Ptolemaeus Main-belt Asteroid
Discovered on 2 August 1949 by K. Reinmuth at Heidelberg.
Where Ptolemaeus is today
Seen from above the solar system on 2026-10-14: Ptolemaeus is 2.45 au from the Sun and 2.44 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 4001 |
| Provisional designation | 1949 PV |
| Orbit class | Main-belt Asteroid |
| Diameter | 4.64 km (#11,351 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.392 |
| Spectral type | S |
| Absolute magnitude (H) | 13.74 |
| Orbital period | 3.46 years |
| Semi-major axis | 2.29 au |
| Perihelion – aphelion | 1.89 – 2.68 au |
| Eccentricity | 0.172 |
| Inclination | 5.46° |
| Closest distance between its orbit and Earth's (MOID) | 0.884 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also discovered on 2 August 1949
- (1682) Karel
- (1820) Lohmann
- (2465) Wilson
- (2591) Dworetsky
- (3020) Naudts
- (3183) Franzkaiser
- (3938) Chapront
- (4979) Otawara
- (6260) Kelsey