Detecção de planetas nos dados do Kepler

Abstract

bstract In this thesis, we present results about the complete characterization of dynamical parameters in three planetary systems, Kepler-46, Kepler-419 and Kepler-59, through the analysis of the transit timing variations (TTVs) of Kepler-46b, Kepler-419b and Kepler-59b and c, respectively. The analysis is based on the TTVs inversion method and uses the Bayesian inference algorithm MultiNest, which allows to make parameter inference and, in the presence of more than one solution, to determine the one with the maximum probability. This algorithm is coupled with an efficient N-body integrator, adapted from the popular algorithm Swift to determine the transits times. The results show two systems with a transiting planet and a non-transiting planet, and one system where the two planets transit. In the first two systems, the planets have masses and radii of giant planets, while in the last system, one planet is a super-Earth and the other a sub-Neptune. The results show that the technique used here is sufficient to find complete solutions of the planets through planetary transits and TTVs. For Kepler-46, the mass of the planet Kepler-46b is determined for the first time and it is suggested that Kepler-46c, that presently does not transit, will begin to transit in the next years. For the Kepler-419 system, the obtained parameter values are comparable to solutions obtained by other authors trough measurements of radial velocity. This fact demonstrates that the technique of TTVs detection alone is able to robustly characterize the mass and orbital parameters of planetary systems. Finally, for Kepler-59, the planetary masses of Kepler-59b and Kepler-59c are determined for the first time. The TTV fit provides information about the density of the planets, showing that the innermost one would have lost its H and He envelopes due to effects, like photo-evaporation, caused by the central star.