Finding Stable Fits for Extrasolar Planetary Systems

Several problems with radial velocity determination of orbital elements call for dynamical studies. One of them is that, due to uncertainties in radial velocity data and complex dynamical behavior, the best fit obtained for systems with planets experiencing strong interactions, like HD202206 and HD160691, are most often not stable. For those two systems, we show how a careful stability analysis constrained by χ2 from radial velocity data (mostly from the Geneva Observatory research team) can lead to a stable fit.