Characterization of Earth-like planets around M-dwarfs with SPIRou Baptiste Klein

le 23 nov 2018 de11h00à 13h002018/11/23 2018/11/23

Over the past three decades, ~ 3000 exoplanets have been confirmed through different methods such as transit follow-up and Doppler spectroscopy. However, due to the limitation in instrumental precision, only a handful of Earth-like planets have been detected in the Habitable Zone (HZ) of their host star. SPIRou is a new infrared spetropolarimeter which is currently being installed at the Canada-France-Hawaii Telescope (CFHT). Thanks to its unrivalled precision of 1 m/s in the bands Y to H, SPIRou will be able to detect Earth-like planets in the HZ of M dwarfs which represent ~ 80 % of the nearby stars. 
However, the Radial Velocity (RV) signal obtained with SPIRou is likely to be polluted by the stellar magnetic activity which is particularly intense on M dwarfs (i.e. with an amplitude greater than the one of the planetary perturbation). Hence the need to combine observational strategies to efficient data processing tools in order to lower, and even to filter out, the stellar jitter. Moreover, unveiling the true number of planets embedded in a given RV signal is a complex but trendingissue that needs advanced post-processing tools.
After a general introduction to exoplanet detection (i.e. historical context, methods, instruments and issues), I will dedicate this seminar to the filtration of the stellar RV jitter and the estimation of the number of planets in a given RV dataset with an application on our recent work carried out on the TRAPPIST-1 planetary system.