[Previous] | [ 10] | [Next]

[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 m_s and semi-major axis a_s, orbiting around a planet of mass M₀, under the slow evolution of (1) M₀, (2) m_s and (3) the variation of the specific angular momentum of the satellite, J_s, 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 dJ_s/dt and by m_s/(M₀ + m_s), 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 m_sa_s.

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.

[Previous] | [ 10] | [Next]

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