139 Juewa
| Discovery | |
|---|---|
| Discovered by | James Craig Watson |
| Discovery date | 10 October 1874 |
| Designations | |
| Main belt | |
| Orbital characteristics | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 121.07 yr (44222 d) |
| Aphelion | 3.26884 AU (489.012 Gm) |
| Perihelion | 2.29261 AU (342.970 Gm) |
| 2.78073 AU (415.991 Gm) | |
| Eccentricity | 0.17553 |
| 4.64 yr (1693.7 d) | |
|
Average orbital speed
|
17.72 km/s |
| 60.2817° | |
| 0° 12m 45.187s / day | |
| Inclination | 10.9127° |
| 1.83417° | |
| 165.566° | |
| Earth MOID | 1.29967 AU (194.428 Gm) |
| Jupiter MOID | 1.7064 AU (255.27 Gm) |
| Jupiter Tisserand parameter | 3.285 |
| Physical characteristics | |
| Dimensions |
156.60±2.8 km 161.43±7.38 km |
| Mass | (5.54±2.20)×1018 kg |
|
Mean density
|
2.51±1.05 g/cm3 |
|
Equatorial surface gravity
|
0.0438 m/s² |
|
Equatorial escape velocity
|
0.0828 km/s |
| 20.991 h (0.8746 d) | |
|
0.0557±0.002 0.0444±0.0164 |
|
| Temperature | ~167 K |
| CP (Tholen) | |
| 7.78, 7.924 | |
139 Juewa (/dʒuːˈeɪwɑː/ jew-AY-wah) is a very large and dark main belt asteroid. It is probably composed of primitive carbonaceous material. It was the first asteroid discovered from China.
Juewa was discovered from Beijing by the visiting American astronomer James Craig Watson on 10 October 1874; Watson was in China to observe the transit of Venus. Watson asked Prince Gong to name the asteroid. Gong's choice was 瑞華星 (roughly, "Star of China’s Fortune"). Watson used only the first two characters, transliterating them as Juewa according to the conventions of his time (in modern pinyin, it would be transliterated as ruìhuá).
There have been three reported stellar occultations by Juewa, most recently on 26 September 2007.
13-cm radar observations of this asteroid from the Arecibo Observatory between 1980 and 1985 were used to produce a diameter estimate of 172 km. Based upon radar data, the near surface solid density of the asteroid is 1.5+0.5
−0.5 g cm−3.
...
Wikipedia