Ophelia (moon)

Last updated
Ophelia
Cordelia Ophelia Voyager 2 labeled.png
Ophelia (top), Cordelia (bottom), and Uranus's narrow rings photographed from afar by Voyager 2 on 21 January 1986
Discovery [1]
Discovered by Richard J. Terrile / Voyager 2
Discovery dateJanuary 20, 1986
Designations
Designation
Uranus VII
Pronunciation /ˈfliə/ [2]
Adjectives Ophelian /ɒˈfliən/ [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
Group ring shepherd
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)
  1. Only two dimensions are known; the third dimension has been assumed to equal the smaller known dimension.

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]

Contents

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 the 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

  1. 1 2 3 4 5 Calculated on the basis of other parameters.

References

  1. 1 2 Smith, B. A. (1986-01-27). "Satellites and Rings of Uranus". IAU Circular. 4168. Retrieved 2011-10-31.
  2. Benjamin Smith (1903). The Century Dictionary and Cyclopedia.
  3. "Ophelian" . Oxford English Dictionary (Online ed.). Oxford University Press.(Subscription or participating institution membership required.)
  4. 1 2 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 . S2CID   118616209.
  5. 1 2 3 4 5 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. Bibcode:2001Icar..151...69K. doi:10.1006/icar.2001.6597.
  6. 1 2 3 French, Richard G.; Hedman, Matthew M.; Nicholson, Philip D.; Longaretti, Pierre-Yves; McGhee-French, Colleen A. (2024-03-15). "The Uranus system from occultation observations (1977–2006): Rings, pole direction, gravity field, and masses of Cressida, Cordelia, and Ophelia". Icarus. 411: 115957. arXiv: 2401.04634 . doi:10.1016/j.icarus.2024.115957. ISSN   0019-1035.{{cite journal}}: CS1 maint: article number as page number (link)
  7. 1 2 3 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. Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008.
  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. S2CID   250909885.