Ophelia (moon)
Moon of Uranus
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Ophelia is a moon of Uranus. It was discovered from the images taken by Voyager 2 on January 20, 1986, and was given the temporary designation S/1986 U 8.[1] It was not seen again until the Hubble Space Telescope recovered it in 2003.[7][9] Ophelia was named after the daughter of Polonius, Ophelia, in William Shakespeare's play Hamlet. It is also designated Uranus VII.[10]
Ophelia (top), Cordelia (bottom), and Uranus's narrow rings photographed from afar by Voyager 2 on 21 January 1986. The moons appear smeared due to their orbital motion during the image exposure. | |
| Discovery[1] | |
|---|---|
| Discovered by | Richard J. Terrile / Voyager 2 |
| Discovery date | January 20, 1986 |
| Designations | |
Designation | Uranus VII |
| Pronunciation | /oʊˈfiːliə/ oh-FEE-lee-ə[2] |
| Adjectives | Ophelian /oʊˈfiːliən/ oh-FEE-lee-ən[3] |
| Orbital characteristics[4] | |
| 53763.390±0.847 km | |
| Eccentricity | 0.00992±0.000107 |
| 0.37640039±0.00000357 d | |
Average orbital speed | 10.39 km/s[a] |
| Inclination | 0.10362°±0.055° (to Uranus's equator)[4] |
| Satellite of | Uranus |
| Physical characteristics | |
| Dimensions | 54 × 38 × 38 km[5][note 1] |
| ~5900 km2[a] | |
| Volume | 40800±50.4% km3[6] |
| Mass | (3.57±0.32)×1016 kg[6] |
Mean density | 0.87+0.89 −0.30 g/cm3[6] |
| ~0.003–0.007 m/s2[a] | |
| ~0.013–0.016 km/s[a] | |
| synchronous[5] | |
| zero[5] | |
| Albedo | 0.065±0.01[7] 0.07[8] |
| Temperature | ~65 K[a] |
| 23.26 (at opposition) | |
| |
Other than its orbit,[4] size of 54 km × 38 km (34 mi × 24 mi),[5] and geometric albedo of 0.065,[7] little is known about it. In images taken by Voyager 2, Ophelia appears as an elongated object, with its major axis pointing towards Uranus. The ratio of axes of Ophelia's prolate spheroid is 0.7 ± 0.3.[5]
Ophelia acts as the outer shepherd satellite for Uranus's ε ring.[11] The orbit of Ophelia is within the synchronous orbit radius of Uranus, and is therefore slowly decaying due to tidal forces.[5]
See also
Notes
- Calculated on the basis of other parameters.