The study of exoplanets has revolutionized our understanding of planetary systems beyond our solar system. As of April 2024, 5 609 exoplanets have been discovered with 728 of them being well-characterized. Transiting exoplanets offer unique insight into the true nature of planetary systems. By combining the strengths of photometric and radial velocity measurements we can ascertain their precise radius, mass, and overall density. This, in turn, enables us to gain insights into their internal structure and chemical composition. Also, by studying a broad range of exoplanets around different spectral types of stars, we gain a deeper understanding of occurrence rates and diverse characteristics across various orbital periods and irradiation levels.
My PhD has been mainly focused on the deep analysis and detrending of TESS light curves to refine the planetary parameters, identify additional transits, and model the stellar activity. The launch of TESS in 2018 significantly expanded our capacity to discover and study transiting exoplanets, particularly those orbiting nearby and bright stars, enhancing the prospects for follow-up radial velocity. Unlike Kepler’s focus on faint stars, TESS has filled a critical gap in our knowledge by delivering a rich sample of giant exoplanets around massive, hot stars, a population previously underrepresented in exoplanet discoveries. This in turn, motivated us to start an ambitious radial velocity campaign using CORALIE and HARPS spectrographs to expand this population. This program led in the discovery of numerous false positives and discovery of 17 well-characterized exoplanets that brings us a step closer in understanding how planets form and evolve under intense stellar radiation. Moreover, I participated in the ESPRESSO campaign dedicated to the detection and precise mass-characterization of warm mini-Neptune planets that transit FGK dwarfs which are not expected to suffer strong irradiation nor evaporation. My contribution to the TESS light curve analysis in this program validated several candidates, set constraints on the rotation period, confirmed the true orbital period, and led in the detection of additional transiting signals. That includes the detection of a long-period warm mini-Neptune in a multi-planet system. Additionally, the CHEOPS mission complemented this campaign by performing targeted photometric observations that constrain their ephemerides and enhance the radius precision. My research has also included extensive work with EulerCam instrument on the Swiss Euler Telescope, focusing on high-precision photometric observations to validate TESS exoplanet candidates, refine the ephemerides of known planets, and enhance the radii measurements.
The future of exoplanet research will undoubtedly rely on the continued synergy between ground-based facilities and space missions. This collaborative approach will allow us to not only discover a wider variety of exoplanets but also to delve deeper into their atmospheres, unlocking the secrets of their formation, evolution, and potential for harboring life.
