05/mai/17 – The Long-term Evolution of Aegaeon, Methone, Anthe, and Pallene (Marco Muñoz, UNESP)

Four small Saturnian moons have been recently discovered by the Cassini spacecraft, near and gravitationally linked to Mimas, namely Aegaeon, Methone, Anthe, and Pallene. They are embedded in arcs or rings form by micrometric dusty material for which most probably they are the source. In this work, we have explored the stability and long-term dynamical evolution of those small moons, through detailed numerical simulations and frequency analysis. The dynamical system is formed by an oblate Saturn, considering its gravity coefficients, or zonal harmonics up to J₆, the five largest satellites near the region, namely Janus, Epimetheus, Mimas, Enceladus, and Tethys and the four small moons. Along with the moons, a wide region of the geometric phase space, a vs e, surrounding them is explored with thousands of test particles. We have produced diffusion maps by performing a frequency analysis of the particles, to gain a better understanding of the global dynamical behavior of the region, as well as their implications for the origin and evolution of the dusty ring/arcs. We found that all the four small moons are long-term stable (at least up to 0.5 Myr) and remain well trapped in resonances with Mimas, except for Pallene, which is non-resonant. We have identified the main mean motion resonances driving the dynamical evolution of particles in the region. Additionally, we have studied the effect of solar radiation pressure on the stability of μm-sized particles. We will present some preliminary results regarding the evolution and stability of the Pallene ring.