61 Danaë
| Discovery | |
|---|---|
| Discovered by | H. Goldschmidt |
| Discovery site | Paris |
| Discovery date | 9 September 1860 |
| Designations | |
| (61) Danaë | |
| Pronunciation | /ˈdæneɪ.iː/ |
Named after | Danaë (Greek mythology) |
| 1953 RL1 · A917 SM | |
| main-belt · (outer) background | |
| Adjectives | Danaëan /dæneɪˈiːən/ |
| Orbital characteristics | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 151.67 yr (55,398 days) |
| Aphelion | 3.4798 AU |
| Perihelion | 2.4840 AU |
| 2.9819 AU | |
| Eccentricity | 0.1670 |
| 5.15 yr (1,881 days) | |
| 157.11° | |
| 0° 11m 29.04s / day | |
| Inclination | 18.212° |
| 333.72° | |
| 12.695° | |
| Physical characteristics | |
| Dimensions | 82.04±4.3 km 82.52±2.73 km 83.56±1.02 km 85.125±1.962 km 85.937±2.151 km 91.00±3.50 km |
| Mass | (2.89±2.78)×1018 kg |
Mean density | 9.81±9.49 g/cm3 |
| 11.45 h 11.547±0.001 h | |
| 0.181±0.034 0.203±0.014 0.2065±0.0472 0.216±0.006 0.2224±0.025 | |
| Tholen = S SMASS = S B–V = 0.852 U–B = 0.402 | |
| 7.56±0.10 · 7.68 · 7.78±0.25 | |
61 Danaë (/ˈdæneɪ.iː/) is a stony (S-type) asteroid in the outer asteroid belt's background population, approximately 84 kilometer in diameter. It was discovered by French astronomer Hermann Goldschmidt on 9 September 1860, from his balcony in Paris, France. Goldschmidt was ill when asked to name the asteroid, and requested his fellow asteroid-hunter Robert Luther to name it instead. Luther chose to name it after Danaë, the mother of Perseus in Greek mythology. Danaë was the first asteroid to have a diacritical character in its official name.
The asteroid is orbiting the Sun with a period of 5.15 years and is rotating on its axis once every 11.45 hours. In 1985, a study of lightcurve data suggested that Danaë may have a moon. If so, the main body would be an ellipsoid measuring 85 km × 80 km × 75 km (53 mi × 50 mi × 47 mi), and the moon would orbit 101 kilometres (63 mi) away, measuring 55 km × 30 km × 30 km (34 mi × 19 mi × 19 mi). The density of both would be 1.1 g/cm3.