Physical characteristics and non-keplerian orbital motion of "propeller" moons embedded in Saturn's rings

Abstract

We report the discovery of several large "propeller" moons in the outer part of Saturn's A ring, objects large enough to be followed over the 5-year duration of the Cassini mission. These are the first objects ever discovered that can be tracked as individual moons, but do not orbit in empty space. We infer sizes up to 1--2 km for the unseen moonlets at the center of the propeller-shaped structures, though many structural and photometric properties of propeller structures remain unclear. Finally, we demonstrate that some propellers undergo sustained non-keplerian orbit motion. (Note: This arXiv version of the paper contains supplementary tables that were left out of the ApJL version due to lack of space).

arXiv comment9 pages, 4 figures; Published in ApJL

References in corpus (3)

• Cassini Imaging of Saturn's Rings II: A Wavelet Technique for Analysis of Density Waves and Other Radial Structure in the Rings
• The population of propellers in Saturn's A Ring
• An analytic parameterization of self-gravity wakes in Saturn's rings, with application to occultations and propellers

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