(16555) Nagaomasami Main-belt Asteroid
Discovered on 31 October 1991 by Endate, K., Watanabe, K. at Kitami.
Masami Nagao (1966-1984) was a Japanese amateur astronomer who died in a traffic accident. His parents, friends of one of the discoverers, constructed an astronomical observatory and donated its equipment to a company active in the popularization of astronomy.Naming citation (20060809/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Nagaomasami is today
Seen from above the solar system on 2026-10-14: Nagaomasami is 2.96 au from the Sun and 3.89 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 16555 |
| Provisional designation | 1991 US3 |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.62 km (#8,090 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.279 |
| Absolute magnitude (H) | 13.41 |
| Orbital period | 4.14 years |
| Semi-major axis | 2.58 au |
| Perihelion – aphelion | 2.15 – 3.00 au |
| Eccentricity | 0.164 |
| Inclination | 15.5° |
| Closest distance between its orbit and Earth's (MOID) | 1.21 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Masami
All asteroids named after someone called Masami