Tidal, dynamical and spin evolution of the Kepler 62 planetary system

Due to observational bias, the observed planetary systems are usually close-in and therefore likely to be subjected to tides. About 23% of the Kepler mission's planetary candidates are found in multiple systems close to their host stars. In these systems, the innermost planets' orbits are simultaneously perturbed by star-planet tidal interactions and by planet-planet gravitational forces [1]. We developed a code to study the tidal and dynamical evolution of multiple planet systems and we present here a study of the Kepler-62 system [2]. This recently discovered system hosts 5 planets. As two of these planets are in the insolation habitable zone, it is interesting to study their orbital evolution as well as their spin states. These quantities are important data for climate modeling. We find that this system is unstable when the simulations are run without tides and General Relativity. However if we assuming a certain dissipation for the planets, we find it stable for at least ten million years. In this case, we also find that the obliquities of the three inner planets are greatly influenced by tides, while the obliquities of the two outer planets oscillate around their initial value. We explored the parameter space of the different planets dissipation and different initial obliquities.