Dynamics of two planets in coorbital motion
Abstract
We study the stability regions and families of periodic orbits of two planets locked in a coorbital configuration. We consider different ratios of planetary masses and orbital eccentricities; we also assume that both planets share the same orbital plane. Initially, we perform numerical simulations over a grid of osculating initial conditions to map the regions of stable/chaotic motion and identify equilibrium solutions. These results are later analysed in more detail using a semianalytical model.
Apart from the wellknown quasisatellite orbits and the classical equilibrium Lagrangian points L_{4} and L_{5}, we also find a new regime of asymmetric periodic solutions. For low eccentricities these are located at (∆λ, ∆ϖ) = (+/60°, /+120°), where ∆λ is the difference in mean longitudes and ∆ϖ is the difference in longitudes of pericentre. The position of these antiLagrangian solutions changes with the mass ratio and the orbital eccentricities and are found for eccentricities as high as ~0.7.
Finally, we also applied a slow mass variation to one of the planets and analysed its effect on an initially asymmetric periodic orbit. We found that the resonant solution is preserved as long as the mass variation is adiabatic, with practically no change in the equilibrium values of the angles.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 September 2010
 DOI:
 10.1111/j.13652966.2010.16904.x
 arXiv:
 arXiv:1004.0726
 Bibcode:
 2010MNRAS.407..390G
 Keywords:

 methods: analytical;
 methods: numerical;
 celestial mechanics;
 planets and satellites: general;
 planetary systems;
 Astrophysics  Earth and Planetary Astrophysics
 EPrint:
 9 pages, 11 figures