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F. Spahn, K. -U. Thiessenhusen, J. Schmidt (University Potsdam, Germany)
The dynamics of dust particles launched from the surface of the Saturnian satellite Enceladus is studied. They move influenced by Saturn's magnetic field, Sun's radiation and the gravitational fields of Enceladus and Saturn. In the latter case also the higher harmonics (up to J2) of gravitational field caused by the oblateness of Saturn have been considered. In a first step we have chosen the equilibrium gain potential according to Horanyi et al. ( Icarus 97 (1992), 248) whereas the size of the dust is a free parameter. A few million particles have been simulated according to the ejecta distributions caused by interplanetary as well as E ring impactors onto Enceladus (Colwell, Icarus 106 (1993), 536). Shortly after launch from Enceladus, we found two major streams departing the satellite in almost all cases of the ejecta velocity distributions. Most of the material is migrating into the E ring in a direction away from Saturn. In this way an asymmetry in the radial optical depth profile of the E ring around the orbit of Enceladus is initially injected. Long term simulations, which have to be run for several seasons of Saturn, should clear whether this initially injected radial asymmetry is wiped out by the effects of radiation, magnetic field, and oblateness or whether it is kept but spread over the whole range of the E ring. Analytically estimates of the Gaussian equations for the dynamics of the orbital elements point to the latter. The specific shape of the optical depth profile of the E ring is then determined by certain sources and sinks (all moons and rings) of E ring dust. This is going to be modeled by solving numerically a balance equation of Master-type.
The author(s) of this abstract have provided an email address for comments about the abstract: FSpahn@agnld.uni-potsdam.de