Resumo:
One of the most promising topics in modern astronomy is the discovery and characterization of extrasolar planets. Space missions dedicated to search exoplanets produced a formidable amount of data. In particular the Kepler mission contributed for thousands of new exoplanets detection. In this thesis we performed a study of the detection and confirmation process of exoplanets. We have developed a modification in an algorithm of correction of sudden changes in CoRoT (Convection, Rotation and planetary Transits) satellite chromatic light curves. In our implementation we adopted a robust statistics and a better management and we show it reduces the systematic variations of light curves and improves the probability of detection of exoplanets when compared to the original algorithm. All the chromatic light curves of the CoRoT satellite (a total of 65,655) were analyzed with our algorithm in this thesis . We rediscovered all CoRoT exoplanets that where published and found in chromatic light-curves. In addition, dozens of new candidates were found in this work. Spectroscopic measurements for eleven of our candidates host stars were available at the ESO Science Archive Facility. We calculated stellar parameters for three candidate host stars that presented a greater number of spectroscopic observations. Among them the radial velocity measurements allowed to confirm a new exoplanet. The exoplanet found in this work orbits a star with 0.79-0.08+0.09 solar radii, with a period of 6.71837+-0.00001 days, 0.15+-0.1 Mjup and 0.57-0.05+0.06 Rjup. The analysis of the parameters found in the two other candidates that we have spectroscopic measurements of the host stars suggest the existence of possible planetary companions.
