- 990 Yerkes at AstDyS-2, Asteroids—Dynamic Site
- 990 Yerkes at the JPL Small-Body Database
| Discovery | |
|---|---|
| Discovered by | G. Van Biesbroeck |
| Discovery site | Williams Bay |
| Discovery date | 23 November 1922 |
| Designations | |
| (990) Yerkes | |
| Pronunciation | /ˈjɜːrkiːz/ |
| 1922 MZ | |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 102.46 yr (37425 days) |
| Aphelion | 3.2477 AU (485.85 Gm) |
| Perihelion | 2.0916 AU (312.90 Gm) |
| 2.6696 AU (399.37 Gm) | |
| Eccentricity | 0.21652 |
| 4.36 yr (1593.2 d) | |
| 216.84° | |
| 0° 13m 33.456s / day | |
| Inclination | 8.7872° |
| 353.971° | |
| 9.4832° | |
| Physical characteristics | |
Mean radius | 9.23±0.6 km |
| 24.56 h (1.023 d) | |
| 24.45 ± 0.05[2] h | |
| 0.1303±0.018 | |
| 11.7 | |
990 Yerkes is a main belt asteroid discovered by Belgian-American astronomer George Van Biesbroeck in 1922, and named after the Yerkes Observatory.
Photometric observations of this asteroid collected during 2009 show a rotation period of 24.45 ± 0.05 hours with a brightness variation of 0.35 ± 0.05 magnitude.[2]