Hamilton, D.P and A.V. Krivov 1996. Circumplanetary dust dynamics:
Effects of solar gravity, radiation pressure, planetary oblateness,
and electromagnetism. Icarus 123, 503-523.
We consider the motions of circumplanetary objects perturbed
simultaneously by solar gravity, radiation pressure, planetary
oblateness, and electromagnetic forces. Confining ourselves to the
planar case, but retaining all nonlinear terms in the eccentricity, we
rewrite the orbit-averaged equations for the sum of the four
perturbations as a semicanonical system. We derive a conserved
integral of the motion which is valid for initially elliptic orbits of
arbitrary size and shape. This integral is used to investigate the
phase space qualitatively, and to show how the eccentricity and apses
line evolve for various strengths of the perturbation forces. We find
several different classes of motion, and show that near certain
critical initial conditions, small variations in parameters such as
particle size or initial semimajor axis can cause dramatic changes in
a particle's orbit. This effect is important in Saturn's E ring and
for Phobos dust. We apply our model to dusty ejecta launched from
several moons -- Phobos, Deimos, Elara, and Enceladus -- and to the
motions of Elara itself. In each case, we compare our analytic results
to numerical integrations of the full Newtonian equations of motion.
Return
to Doug Hamilton's Publication List