Cordelia (moon)

Not to be confused with the tanker ship Cordelia Moon.

Cordelia is the innermost known 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.^[1] It was not detected again until the Hubble Space Telescope observed it in 1997.^[7][9] Cordelia takes its name from the youngest daughter of Lear in William Shakespeare's King Lear. It is also designated Uranus VI.^[10]

Cordelia

Cordelia (Imaged 24 January 1986)
Discovery[1]
Discovered by	Richard J. Terrile / Voyager 2
Discovery date	January 20, 1986
Designations
Designation	Uranus VI
Pronunciation	/kɔːrˈdiːliə/[2]
Adjectives	Cordelian[3]
Orbital characteristics[4]
Semi-major axis	49751.722±0.149 km
Eccentricity	0.00026±0.000096
Orbital period (sidereal)	0.33503384±0.00000058 d
Inclination	0.08479°±0.031° (to Uranus' equator)
Satellite of	Uranus
Group	ring shepherd
Physical characteristics
Dimensions	50 × 36 × 36 km[5][note 1]
Surface area	~5200 km2[a]
Volume	33900±34.9% km3[6]
Mass	(6.08±0.57)×1016 kg[6]
Mean density	1.79+0.97 −0.49 g/cm3[6]
Surface gravity	~0.006–0.013 m/s2[a]
Escape velocity	~0.018–0.021 km/s[a]
Synodic rotation period	synchronous[5]
Axial tilt	zero[5]
Albedo	0.06±0.01[7] 0.07[8]
Temperature	~65 K[a]
Only two dimensions are known; the third dimension has been assumed to equal the smaller known dimension.

Other than its orbit,^[4] size of 50 × 36 km,^[5] and geometric albedo of 0.06,^[7] 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.^[5]

Cordelia acts as the inner shepherd satellite for Uranus's ε ring.^[11] Cordelia's orbit is within Uranus's synchronous orbit radius, and is therefore slowly decaying due to tidal deceleration.^[5]

Cordelia is very close to a 5:3 orbital resonance with Rosalind.^[12]

See also

• Moons of Uranus

Notes

1. Calculated on the basis of other parameters.

References

1. 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. Jennifer Bates (2010). Hegel and Shakespeare on Moral Imagination. p. 102.
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. Bibcode:1998AJ....115.1195J. doi:10.1086/300263.
5. 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. 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.
7. 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. 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.
12. Murray, Carl D.; Thompson, Robert P. (1990-12-06). "Orbits of shepherd satellites deduced from the structure of the rings of Uranus". Nature. 348 (6301): 499–502. Bibcode:1990Natur.348..499M. doi:10.1038/348499a0. ISSN 0028-0836. S2CID 4320268.

External links

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