Physical properties of Uranian delta ring from a possible density wave

The Voyager PPS stellar occultation observations of the Uranian δ ring show evidence for a moonlet interior to the δ ring, which excites a density wave at 48,299.6 ± 0.4 km. The identification of a density wave is from the wavelength and amplitude behavior and the morphology of the observed feature. Sixty-five discrete locations are possible for the orbit of this unseen moonlet. Allowing for these 65 possible locations, we find the surface mass density of the δ ring 5 ⪅ σ ⪅ 10 g/cm ², the viscosity 10 ⪅ ν ⪅ 40 cm ²/sec, and the local ring height 7 ⪅ h ⪅ 20 m. These values are comparable to some parts of Saturn's rings. All of the inner and outer first order Lindblad resonances were calculated for the 65 possible moonlet locations. The 65 locations for the moonlet are labeled by azimuth number of m of the resonance associated with each location that would excite the density wave in the δ ring. Moonlet 101, located at 47,984.1 ± 0.4 km has resonances which can also shepherd the inner edge of the δ ring and the outer edge of the γ ring.