(23109) Masayanagisawa Outer Main-belt Asteroid
Discovered on 30 December 1999 by LONEOS at Anderson Mesa.
Masahisa Yanagisawa (b. 1955), planetary scientist at the University of Electro-Communications, Tokyo, works on experimental studies of collision phenomena and makes observations of meteoroid impacts on the Moon.Naming citation (20120506/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Masayanagisawa is today
Seen from above the solar system on 2026-10-14: Masayanagisawa is 3.46 au from the Sun and 3.67 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 23109 |
| Provisional designation | 1999 YD13 |
| Orbit class | Outer Main-belt Asteroid |
| Diameter | 9.45 km (#5,449 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0790 |
| Absolute magnitude (H) | 14.02 |
| Orbital period | 5.79 years |
| Semi-major axis | 3.22 au |
| Perihelion – aphelion | 2.76 – 3.69 au |
| Eccentricity | 0.145 |
| Inclination | 7.64° |
| Closest distance between its orbit and Earth's (MOID) | 1.78 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.