Are retrograde resonances possible in multi-planet systems?
Julie Gayon, Eric Bois (Nice Sophia-Antipolis University, CNRS, Observatoire de la Cote d’Azur, Laboratoire Cassiopee, France) Most multi-planetary systems are characterized by hot-Jupiters close to their central star, moving on eccentric orbits. From a dynamical point of view, compact multi-planetary systems form a specific class of the general N-body problem (where N>3). Moreover, extrasolar planets are found in prograde orbits about their host star, and often in mean motion resonances (MMR). In a first step, we study theoretically a new stabilizing mechanism suitable for compact two-planet systems. This mechanism involves counter-revolving orbits forming a retrograde MMR. In a second step, we investigate the feasibility of planetary systems hosting counter-revolving planets. Dynamical stability, observations, and formation processes of these systems are analyzed and discussed. To characterize the dynamical behavior of multi-dimensional planetary systems, we apply our technique of gl