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's 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] little 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.