| Minorplanet: | yes |
| Background: |
|
| 729 Watsonia | |
| Mpc Name: | (729) Watsonia |
| Alt Names: | 1912 OD |
| Discovered: | 9 February 1912 |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Eccentricity: | 0.096988 |
| Semimajor: | 2.7594AU |
| Perihelion: | 2.4917AU |
| Aphelion: | 3.027abbr=onNaNabbr=on |
| Period: | 4.58 yr (1674.2 d) |
| Inclination: | 18.042° |
| Asc Node: | 124.388° |
| Arg Peri: | 88.376° |
| Mean Motion: | / day |
| Observation Arc: | 98.79 yr (36082 d) |
| Uncertainty: | 0 |
| Abs Magnitude: | 9.31 |
| Rotation: | 25.23abbr=onNaNabbr=on |
| Mean Radius: | km |
729 Watsonia is a rare-type asteroid and namesake of the Watsonia family from the central region of the asteroid belt. It was named after the Canadian-American astronomer James C. Watson. Watsonia occulted the star 54 Leonis (HIP 53417, a 4.3 Magnitude Star) on 2013 Mar 03 at 01:48.
This object is the namesake of the Watsonia family, an Asteroid family of approximately 100 asteroids that share similar spectral properties and orbital elements; hence they may have arisen from the same collisional event. All members have a relatively high orbital inclination.