Synergy between stellar physics and planetology, a pathway for high-resolution spectroscopy of exoplanet atmosphere

Spectroscopy of exoplanet atmospheres at high-resolving power is a determinant technique for remote atmospheric characterisation of exoplanet atmospheres. However, the non-stationary stellar spectrum affects the position and/of shift of line profiles and creates a non-negligible source of noise that can alter or even prevent detection. I will present three examples of transmission and emission spectroscopy for HD 189733-b and 51 Pegasi b for which the correction for the stellar convection-related activity is included in the analysis. There is a significant improvement in planet detectability when removing the stellar spectrum with this method. Moreover, I will also introduce a new approach based on realistic synthetic observables whose innovation and uniqueness is based on the use of 3D hydrodynamical simulations for the atmosphere of both the host star and the planet during the transit.