Long-term Monitoring of Exoplanetary Systems and Transit Timing Variations

Transit Monitoring on the South (TraMoS) is a program dedicated to the study of transiting exoplanets using ground-based instrumentation. The project has been making observations of known planets over the last decade. This data can be complemented with observations from the Transiting Exoplanet Survey Satellite (TESS) to perform a detailed long-baseline analysis of the light curves.

This thesis reports the current status of the survey, including the development of a database to characterize its sample. The team utilizes a semi-automated data reduction pipeline that has been tuned to achieve a high signal-to-noise ratio and prevent errors. In addition, a detailed analysis of four Hot Jupiters is presented: WASP-8b, WASP-43b, WASP-46b, and WASP-50b, each studied over a long observational baseline (> 7 years).

Bayesian tools were applied to refine their planetary and orbital parameters, including limb darkening. A timing analysis of the transit residuals was then performed, comparing three orbital models to conclude on the system dynamics and refine their ephemerides. The reduced χ² indicates that a Keplerian model is the most appropriate for each planet studied, rather than models including orbital decay or apsidal precession. A Lomb-Scargle periodogram analysis of the TTV data revealed no significant periodic signals. Furthermore, upper mass limits for a perturbing body were calculated based on the timing residuals.