(4809) Robertball Main-belt Asteroid
Discovered on 5 September 1928 by M. F. Wolf at Heidelberg.
Mathematician and astronomer Robert Stawell Ball (1840-1913) was one of the most successful popularizers of science of his time. Tutor to the children of the fourth Earl of Rosse and observer at Birr Castle, he later moved to Dublin as Royal Astronomer of Ireland until becoming Lowndean professor at Cambridge in 1893.Naming citation (20041126/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Robertball is today
Seen from above the solar system on 2026-10-14: Robertball is 2.35 au from the Sun and 2.99 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 4809 |
| Provisional designation | 1928 RB |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.45 km (#8,313 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.354 |
| Absolute magnitude (H) | 13.02 |
| Orbital period | 4.11 years |
| Semi-major axis | 2.57 au |
| Perihelion – aphelion | 1.93 – 3.20 au |
| Eccentricity | 0.248 |
| Inclination | 13.7° |
| Closest distance between its orbit and Earth's (MOID) | 0.923 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Robert
- (1955) McMath
- (3514) Hooke
- (3875) Staehle
- (4564) Clayton
- (5109) Robertmiller
- (5308) Hutchison
- (5477) Holmes
- (5585) Parks
- (5636) Jacobson
- (5739) Robertburns
- (5817) Robertfrazer
- (5871) Bobbell
All asteroids named after someone called Robert