(20990) Maryannehervey Main-belt Asteroid
Discovered on 1 September 1983 by H. Debehogne at La Silla.
Mary Anne Hervey (1796–1838) was the wife of Fearon Fallows, an English resident astronomer at the Royal Observatory at the Cape. She often assisted him with his observations, and even made an independent discovery of C/1830 F1 (Great Comet). When Fearon died in 1831 she returned to England, carrying his papers and unpublished data.Naming citation (WGSBN Bull. 4, #3, 6), IAU / Minor Planet Center, via NASA/JPL
Where Maryannehervey is today
Seen from above the solar system on 2026-10-14: Maryannehervey is 2.46 au from the Sun and 3.33 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 20990 |
| Provisional designation | 1983 RL3 |
| Orbit class | Main-belt Asteroid |
| Diameter | 2.91 km (#15,423 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.190 |
| Absolute magnitude (H) | 15.01 |
| Orbital period | 3.20 years |
| Semi-major axis | 2.17 au |
| Perihelion – aphelion | 1.86 – 2.48 au |
| Eccentricity | 0.143 |
| Inclination | 3.06° |
| Closest distance between its orbit and Earth's (MOID) | 0.860 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Mary
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- (12590) Ballantine
- (12627) Maryedwards
- (12628) Acworthorr
- (13412) Guerrieri
All asteroids named after someone called Mary
Also discovered on 1 September 1983
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- (4994) Kisala
- (6368) Richardmenendez
- (7109) Heine
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- (7996) Vedernikov
- (24641) Enver