Astronomy:Ophelia (moon)

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Short description: Moon of Uranus
Ophelia
Opheliamoon.png
Ophelia (image taken 21 January 1986)
Discovery
Discovered byRichard J. Terrile / Voyager 2
Discovery dateJanuary 20, 1986
Designations
Designation
Uranus VII
Pronunciation/ˈfliə/[1]
AdjectivesOphelian /ɒˈfliən/[2]
Orbital characteristics
Mean orbit radius53,763.390 ± 0.847 km[3]
Eccentricity0.00992 ± 0.000107[3]
Orbital period0.37640039 ± 0.00000357 d[3]
Average Orbital speed10.39 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 radius21.4 ± 4 km[4][5][6]
Surface area~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]
Rotation periodsynchronous[4]
Axial tiltzero[4]
Albedo
Physics~64 K[lower-alpha 1]


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

References

Explanatory notes

  1. Jump up to: 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Calculated on the basis of other parameters.

Citations

  1. Benjamin Smith (1903) The Century Dictionary and Cyclopedia
  2. Ophelian (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Ophelian  (Subscription or UK public library membership required.)
  3. Jump up to: 3.0 3.1 3.2 3.3 3.4 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. doi:10.1086/300263. Bibcode1998AJ....115.1195J. 
  4. Jump up to: 4.0 4.1 4.2 4.3 4.4 4.5 4.6 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. doi:10.1006/icar.2001.6597. Bibcode2001Icar..151...69K. 
  5. Jump up to: 5.0 5.1 5.2 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. http://ssd.jpl.nasa.gov/?sat_phys_par. 
  6. Jump up to: 6.0 6.1 Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). http://nssdc.gsfc.nasa.gov/planetary/factsheet/uraniansatfact.html. 
  7. Jump up to: 7.0 7.1 7.2 Karkoschka, Erich (2001). "Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope". Icarus 151 (1): 51–68. doi:10.1006/icar.2001.6596. Bibcode2001Icar..151...51K. 
  8. Smith, B. A. (1986-01-27). "Satellites and Rings of Uranus". IAU Circular 4168. http://www.cbat.eps.harvard.edu/iauc/04100/04168.html#item1. Retrieved 2011-10-31. 
  9. Showalter, M. R.; Lissauer, J. J. (2003-09-03). "Satellites of Uranus". IAU Circular 8194. http://www.cbat.eps.harvard.edu/iauc/08100/08194.html. Retrieved 2011-10-31. 
  10. "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. http://planetarynames.wr.usgs.gov/append7.html. 
  11. Esposito, L. W. (2002). "Planetary rings". Reports on Progress in Physics 65 (12): 1741–1783. doi:10.1088/0034-4885/65/12/201. Bibcode2002RPPh...65.1741E. 

External links