On fitting planetary systems in counter-revolving configurations

Abstract

In Gayon & Bois and Gayon, Bois & Scholl, (i) we studied the theoretical feasibility and efficiency of retrograde mean motion resonances (i.e. two planets are both in orbital resonance and in counter-revolving configuration), (ii) we showed that retrograde resonances can generate interesting mechanisms of stability and (iii) we obtained a dynamical fit involving a counter-revolving configuration that is consistent with the observations of the HD 73526 planetary system. In the present Letter, we present and analyse data reductions assuming counter-revolving configurations for eight compact multiplanetary systems detected through the radial velocity method. In each case, we select the best fit leading to a dynamically stable solution. The resulting data reductions obtained in rms and VAv2 values for counter-revolving configurations are of the same order, and sometimes slightly better than for prograde configurations. In the end, these fits tend to show that, over the eight studied multiplanetary systems, six of them could be regulated by a mechanism involving a counter-revolving configuration. © 2009 The Authors. Journal compilation © 2009 RAS.