Vital Statistics for Uranus’s Rings

Rings of Uranus

Feature Middle Boundary (km) Width Eccentricity Inclination (deg) Optical Depth Type Associated Moons Footnotes Comments
Zeta CC 30,863 8050     ~0.0001 Broad, diffuse   2 Extension of zeta ring
Zeta C 36,639 2960     ~0.0005 Broad, diffuse   2 Extension of zeta ring
dust sheet 38,440 23200     0.005 Broad, diffuse   2 A sheet of material that permeates the ring sytem,
Zeta 39,600 3500     ~0.0045 Broad, diffuse   2 The zeta ring is the innermost ring. Wide and diffuse when originally observed in Voyager images (designated as 1986U2R), the estimated optical depth was much lower the the modern value. This may be due to assumptions about particle albedo and phase function, or actual variation of the ring properties over time and/or wavelength
Six 41,838 1.53 0.00102 0.0607 ~0.3 Narrow, dense   2  
Five 42,234 2.28 0.0019 0.0559 ~0.5 Narrow, dense   2  
Four 42,571 2.33 0.00106 0.032 ~0.3 Narrow, dense   2  
Alpha-4 43,027 3353     0.002 Broad, diffuse   2 Dust ring between Four and Alpha rings
Alpha 44,718 8.46 0.00076 0.015 ~0.4 Narrow, dense   2  
Beta-Alpha 44,879 312     0.002 Broad, diffuse   2 Dust ring between Alpha and Beta rings
Beta 45,661 9.49 0.000442 0.005 ~0.3 Narrow, dense   2  
Eta C 47,201 40     0.02 Narrow, diffuse   2 Extension of Eta ring
Eta 47,176 1.6     ~0.4 Narrow, dense   2  
Gamma 47,627 2.15 0.001092 0 ~0.3 Narrow, dense Ophelia 2 Shape also contains an m=0 mode of 5.15 km amplitude [3].
Delta C 48,289 15     0.03 Narrow, diffuse   2 Extension of the Delta ring
Delta 48,300 4.6   0.001 ~0.5 Narrow, dense Cordelia 2 Shape is dominated by an m=2 mode.
Lambda C 49,936 3.1     0.15 Narrow, diffuse   2 Dust ring interior to Lambda ring
Lambda 50,024 2.3 0. 0. ~0.1 Narrow, diffuse   2 Contains clumps.
Epsilon 51,149 58.1 0.00794 0 0.5 to 2.3 Narrow, dense Cordelia, Ophelia 2 Shepherded by Cordelia and Ophelia.
Nu 67,300 3800 0 0 0.0000056 Broad, diffuse Portia, Rosalind 1,2 Very faint; bounded by Portia and Rosalind.
Mu 97,700 17,000 0 0 0.0000085 Broad, diffuse Mab 1,2 Very faint; peaks at the orbit of Mab.

The table of Uranus’s inner satellites can be found here.

Sources:

  1. Showalter, M.R., and J.J. Lissauer 2006. The second ring-moon system of Uranus: Discovery and dynamics. Science 311, 973-977. DOI:10.1126/science.1122882

  2. Nicholson, P.D., et al. 2018. The rings of Uranus. In M.S. Tiscareno and C.D. Murray (eds.), Planetary Ring Systems, Cambridge University Press, 93-111.

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