Ophelia (moon)

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.[8] It was not seen 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
Ophelia (image taken 21 January 1986)
Discovery
Discovered byRichard J. Terrile / Voyager 2
Discovery dateJanuary 20, 1986
Designations
Designation
Uranus VII
Pronunciation/oʊˈfiːliə/[1]
AdjectivesOphelian /ɒˈfiːliən/[2]
Orbital characteristics
Mean orbit radius
53,763.390 ± 0.847 km[3]
Eccentricity0.00992 ± 0.000107[3]
0.37640039 ± 0.00000357 d[3]
10.39 km/s[lower-alpha 1]
Inclination0.10362 ± 0.055° (to Uranus' equator)[3]
Satellite ofUranus
Groupring shepherd
Physical characteristics
Dimensions54 × 38 × 38 km[4]
Mean radius
21.4 ± 4 km[4][5][6]
~6600 km²[lower-alpha 1]
Volume~41,000 km³[lower-alpha 1]
Mass~5.3×1016 kg[lower-alpha 1]
Mean density
~1.3 g/cm³ (assumed)[5]
~0.0070 m/s²[lower-alpha 1]
~0.018 km/s[lower-alpha 1]
synchronous[4]
zero[4]
Albedo
Temperature~64 K[lower-alpha 1]

    Other than its orbit,[3] radius of 21 km[4] and geometric albedo of 0.08[7] virtually nothing is known about it. At the Voyager 2 images Ophelia appears as an elongated object, the major axis pointing towards Uranus. The ratio of axes of the Ophelia's prolate spheroid is 0.7 ± 0.3.[4]

    Ophelia acts as the outer shepherd satellite for Uranus' ε ring.[11] The orbit of Ophelia is within the synchronous orbit radius of Uranus, and is therefore slowly decaying due to tidal forces.[4]

    See also

    References

    Explanatory notes

    1. Calculated on the basis of other parameters.

    Citations

    1. Benjamin Smith (1903) The Century Dictionary and Cyclopedia
    2. "Ophelian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
    3. Jacobson, R. A. (1998). "The Orbits of the Inner Uranian Satellites From Hubble Space Telescope and Voyager 2 Observations". The Astronomical Journal. 115 (3): 1195–1199. Bibcode:1998AJ....115.1195J. doi:10.1086/300263.
    4. Karkoschka, Erich (2001). "Voyager's Eleventh Discovery of a Satellite of Uranus and Photometry and the First Size Measurements of Nine Satellites". Icarus. 151 (1): 69–77. Bibcode:2001Icar..151...69K. doi:10.1006/icar.2001.6597.
    5. "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. Retrieved 12 December 2008.
    6. Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008.
    7. Karkoschka, Erich (2001). "Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope". Icarus. 151 (1): 51–68. Bibcode:2001Icar..151...51K. doi:10.1006/icar.2001.6596.
    8. Smith, B. A. (1986-01-27). "Satellites and Rings of Uranus". IAU Circular. 4168. Retrieved 2011-10-31.
    9. Showalter, M. R.; Lissauer, J. J. (2003-09-03). "Satellites of Uranus". IAU Circular. 8194. Retrieved 2011-10-31.
    10. "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Archived from the original on 5 March 2016. Retrieved 6 August 2006.
    11. Esposito, L. W. (2002). "Planetary rings". Reports on Progress in Physics. 65 (12): 1741–1783. Bibcode:2002RPPh...65.1741E. doi:10.1088/0034-4885/65/12/201.
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