The dynamic nature of the Adams ring arcs—Fraternite, Egalite (2,1), Liberte, Courage

By considering the finite mass of Fraternite, the dynamic nature of the Adams ring arcs is regarded as caused by the reaction of a test body (a minor arc) through the Lindblad resonance (LR). Assuming the eccentricity of the test body is larger than that of Galatea, this generates several locations along the ring in the neighborhood of Fraternite where the time averaged force on a test body vanishes. These locations appear to correspond to the time dependent configuration of Egalite (2,1), Liberte, and Courage, and seem to be able to account for the dynamics of the arcs. Such a configuration is a dynamic one because the minor arcs are not bounded by the corotation eccentricity resonance (CER) externally imposed by Galatea, but are self-generated by LR reacting to the external fields.