(21625) Seira Main-belt Asteroid
Discovered on 12 July 1999 by LINEAR at Socorro.
Seira Shimoyama (b. 1988) was awarded first place in the 2006 Intel International Science and Engineering Fair for her zoology project. She attends the Urawa Daiichi Girls High School, Urawa-city, Saitama Prefecture, Japan.Naming citation (20060711/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Seira is today
Seen from above the solar system on 2026-10-14: Seira is 2.80 au from the Sun and 2.53 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21625 |
| Provisional designation | 1999 NN2 |
| Orbit class | Main-belt Asteroid |
| Diameter | 3.92 km (#12,934 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.346 |
| Rotation period | 3.08 hours |
| Absolute magnitude (H) | 14.16 |
| Orbital period | 5.51 years |
| Semi-major axis | 3.12 au |
| Perihelion – aphelion | 2.42 – 3.82 au |
| Eccentricity | 0.223 |
| Inclination | 15.6° |
| Closest distance between its orbit and Earth's (MOID) | 1.46 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also discovered on 12 July 1999
- (12571) Occhiogrosso
- (20485) Leaferellec
- (20486) Lemos
- (21626) Matthewhall
- (21646) Joshuaturner
- (21647) Carlturner
- (21648) Gravanschaik