The dynamical structure of the habitable zone in the HD 38529, HD 168443 and HD 169830 systems

Abstract

The dynamical structure of the habitable zone in the multiple exoplanetary systems HD 38529, HD 168443 and HD 169830 is investigated. By using long-time numerical integration and fast chaos-detection methods, it is shown that the habitable zone of all three systems is mostly chaotic. There is a stable region between the two known planets only in the system HD 38529, near the inner edge of the habitable zone, where a third planet could exist. This region is stable for a wide range of orbital eccentricity and mass of the larger outer planet. The stability region is divided by higher-order mean motion resonances, which are studied in detail. It seems that higher-order resonances are important in exoplanetary systems due to the large planetary masses and large orbital eccentricities.