283 Emma
A three-dimensional model of 283 Emma based on its light curve | |
| Discovery | |
|---|---|
| Discovered by | Auguste Charlois |
| Discovery date | 8 February 1889 |
| Designations | |
| (283) Emma | |
| Pronunciation | /ˈɛmə/ |
| A889 CA, 1980 FJ12 | |
| Main belt (Emma) | |
| Orbital characteristics | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 122.26 yr (44655 d) |
| Aphelion | 3.49701 AU (523.145 Gm) |
| Perihelion | 2.59675 AU (388.468 Gm) |
| 3.04688 AU (455.807 Gm) | |
| Eccentricity | 0.14773 |
| 5.32 yr (1942.6 d) | |
Average orbital speed | 17.07 km/s |
| 127.107° | |
| 0° 11m 7.148s / day | |
| Inclination | 7.99162° |
| 304.369° | |
| 53.7020° | |
| Known satellites | 1 (9±5 km) |
| Physical characteristics | |
| Dimensions | 148.06±4.6 km (IRAS) 160±10 km (AO) |
| Mass | 1.38×1018 kg |
Mean density | 0.81±0.08 g/cm3 |
| 6.896 h (0.2873 d) | |
| 0.0262±0.002 (Dark) | |
| 8.72 | |
283 Emma is a large asteroid of the asteroid belt and the namesake of the Emma family. It was discovered by Auguste Charlois on 8 February 1889, in Nice, France. The reason for its name is unknown.
Measurements made with the IRAS observatory give a diameter of 145.70±5.89 km and a geometric albedo of 0.03±0.01. By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of 145.44±7.72 km and a geometric albedo of 0.03±0.01. When the asteroid was observed occulting a star, the results showed a diameter of 148.00±16.26 km.