Ophelia (moon)

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Discovery image of Ophelia (top of image, outside of rings)
Discovered by Richard J. Terrile / Voyager 2
Discovery date January 20, 1986
Orbital characteristics
Mean orbit radius
53,763.390 ± 0.847 km[1]
Eccentricity 0.00992 ± 0.000107[1]
0.37640039 ± 0.00000357 d[1]
10.39 km/s[a]
Inclination 0.10362 ± 0.055° (to Uranus' equator)[1]
Satellite of Uranus
Physical characteristics
Dimensions 54 × 38 × 38 km[2]
Mean radius
21.4 ± 4 km[2][3][4]
~6600 km²[a]
Volume ~41,000 km³[a]
Mass ~5.3×1016 kg[a]
Mean density
~1.3 g/cm³ (assumed)[3]
~0.0070 m/s²[a]
~0.018 km/s[a]
Temperature ~64 K[a]

Ophelia (/ɵˈfliə/ o-FEE-lee-ə) 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.[6] It was not seen until the Hubble Space Telescope recovered it in 2003.[5][7] Ophelia was named after the daughter of Polonius, Ophelia, in William Shakespeare's play Hamlet. It is also designated Uranus VII.[8]

Other than its orbit,[1] radius of 21 km[2] and geometric albedo of 0.08[5] 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.[2]

Ophelia acts as the outer shepherd satellite for Uranus' Epsilon ring.[9] The orbit of Ophelia is within the synchronous orbit radius of Uranus, and therefore the moon is slowly decaying due to tidal forces.[2]

See also[edit]


Explanatory notes

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


  1. ^ 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.  edit
  2. ^ 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.  edit
  3. ^ a b c "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. Retrieved 12 December 2008. 
  4. ^ a b Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008. 
  5. ^ 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.  edit
  6. ^ Smith, B. A. (1986-01-27). "Satellites and Rings of Uranus". IAU Circular 4168. Retrieved 2011-10-31. 
  7. ^ Showalter, M. R.; Lissauer, J. J. (2003-09-03). "Satellites of Uranus". IAU Circular 8194. Retrieved 2011-10-31. 
  8. ^ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 6 August 2006. 
  9. ^ 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.  edit

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