Perturbation of compact planetary systems by distant giant planets

We examine the effect of secular perturbations by giant planets on systems of multiple, lower mass planets orbiting Sun-like stars and compare our results to the statistics of the observed Kepler data. We cannot reproduce the observed excess of single transiting planets by only pumping inclination without driving most systems to dynamical instability. Thus, we expect the underlying planetary population for single transiting planets to contain an intrinsically low multiplicity component. We can reproduce the Kepler statistics and occurrence rates for R < 2R(circle plus). planets with a perturber population consistent with that inferred from radial velocity surveys, but require too many giant planets if we wish to explain all planets with R < 4R(circle plus). These numbers can be brought into agreement if we posit the existence of an equivalent size population of planets below the RV detection limit (of characteristic mass similar to 0.1M(J)). This population would need to be dynamically hot to produce sufficiently strong perturbations and would leave the imprint of high obliquities and eccentricities amongst the surviving planets. The histories of our perturbed populations also produce a significant number of planets that are lost by collision with the star and some that are driven to short orbital periods by the combined action of secular evolution and tidal dissipation. Some of our simulations also produce planetary systems with planets that survive in the habitable zone but have no planets interior to them - much as in the case of our Solar system. Such configurations may occur around a few per cent of FGK stars.