34th Meeting of the AAS Division on Dynamical Astronomy, May 2003
10 Satellites and Rings
Oral, Tuesday, May 6, 2003, 3:25-5:10pm,

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[10.05] Effect of slow variations of parameters for 2 co-orbital satellites and stationary configurations for N co-orbital satellites

B. Sicardy, S. Renner (Observatoire de Paris), V. Dubois (Universite de Nantes)

We study the evolution of a test particle co-orbital with a satellite of mass ms and semi-major axis as, orbiting around a planet of mass M0, under the slow evolution of (1) M0, (2) ms and (3) the variation of the specific angular momentum of the satellite, Js, caused by a torque.

We show that the particle motion is distorted (with respect to the classical horsheshoe and tadpole orbits) in a manner which is entirely described by dJs/dt and by ms/(M0 + ms), for any amplitude of the corotation motion.

Adiabatic invariance arguments show that the long term evolution of the particle motion only depends on the variation of msas.

Generalization can be made when a constant torque is applied to the particle as well. If this torque exhibits a radial gradient, however, then the adiabatic invariance of action is destroyed and the evolution of the system must be studied case by case.

We finally investigate the stationary configurations of N co-orbital satellites with unequal masses. We show that if N is even, a relation between the angular separations of the co-orbitals must be verified to permit an equilibrium, with a two-parameter family of possible masses. If N is odd, then for any angular separations of the co-orbitals, there is a one-parameter family of masses which allows equilibrium. The case N=3 can be solved analytically and will be displayed.

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Bulletin of the American Astronomical Society, 35 #4
© 2003. The American Astronomical Soceity.