Cordelia (moon)
Cordelia (lower-middle, inside of bright ring), discovery image from Voyager 2
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Discovery
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| Discovered by | Richard J. Terrile / Voyager 2 |
| Discovery date | January 20, 1986 |
| Mean orbit radius | 49751.722 ± 0.149 km[1] |
| Eccentricity | 0.00026 ± 0.000096[1] |
| Orbital period | 0.33503384 ± 0.00000058 d[1] |
| Inclination | 0.08479 ± 0.031° (to Uranus' equator)[1] |
| Satellite of | Uranus |
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Physical characteristics
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| Dimensions | 50 × 36 × 36 km[2] |
| Mean radius | 20.1 ± 3 km[2][3][4] |
| Surface area | ~5500 km²[a] |
| Volume | ~38,900 km³[a] |
| Mass | ~4.4×1016 kg[a] |
| Mean density | ~1.3 g/cm³ (assumed)[3] |
| Equatorial surface gravity | ~0.0073 m/s²[a] |
| Escape velocity | ~0.017 km/s[a] |
| Rotation period | synchronous[2] |
| Axial tilt | zero[2] |
| Albedo | |
| Temperature | ~64 K[a] |
Cordelia (
/kɔrˈdiːliə/ kor-dee-lee-ə) is the innermost 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 7.[6] It was not detected again until the Hubble Space Telescope observed it in 1997.[5][7] Cordelia takes its name from the youngest daughter of Lear in William Shakespeare's King Lear. It is also designated Uranus VI.[8]
Other than its orbit,[1] radius of 20 km[2] and geometric albedo of 0.08[5] virtually nothing is known about it. In the Voyager 2 images Cordelia appears as an elongated object with its major axis pointing towards Uranus. The ratio of axes of Cordelia's prolate spheroid is 0.7 ± 0.2.[2]
Cordelia acts as the inner shepherd satellite for Uranus' Epsilon ring.[9] Cordelia's orbit is within Uranus' synchronous orbit radius, and is therefore slowly decaying due to tidal deceleration.[2]
Cordelia is very close to a 5:3 orbital resonance with Rosalind.[10]
[edit] See also
[edit] References
Explanatory notes
Citations
- ^ 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.
- ^ 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.
- ^ a b c "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. http://ssd.jpl.nasa.gov/?sat_phys_par. Retrieved 12 December 2008.
- ^ a b 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. Retrieved 12 December 2008.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. http://planetarynames.wr.usgs.gov/append7.html. Retrieved 6 August 2006.
- ^ 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.
- ^ Murray, C. D.; Thompson, R. P. (1990-12-06). "Orbits of shepherd satellites deduced from the structure of the rings of Uranus". Nature 348: 499 - 502. doi:10.1038/348499a0. http://www.nature.com/nature/journal/v348/n6301/abs/348499a0.html. Retrieved 2012-02-20.
[edit] External links
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