Ophelia (moon)


Ophelia (image taken 21 January 1986)
Discovered byRichard J. Terrile / Voyager 2
Discovery dateJanuary 20, 1986
Uranus VII
AdjectivesOphelian /ɒˈfliən/[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[a]
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[a]
Volume~41,000 km³[a]
Mass~5.3×1016 kg[a]
Mean density
~1.3 g/cm³ (assumed)[5]
~0.0070 m/s²[a]
~0.018 km/s[a]
Temperature~64 K[a]

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]

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


Explanatory notes

  1. ^ a b c d e f g Calculated on the basis of other parameters.


  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. ^ a b c d e 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. ^ a b c d e f g 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. ^ a b c "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. Retrieved 12 December 2008.
  6. ^ a b Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008.
  7. ^ a b c 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.

External links

  • Ophelia Profile by NASA's Solar System Exploration
  • Uranus' Known Satellites (by Scott S. Sheppard)