Magnetic topology and radial-velocity variability of a TWA star from multi-epoch SPIRou observations

Le résumé fourni par la source

We present an ongoing analysis of one of the TW Hydrae Association stars observed with SPIRou over three seasons. The goal of this work is to characterize its magnetic properties and to investigate the origin of its radial-velocity variability.We apply Gaussian process regression to the longitudinal magnetic field measurements to constrain the stellar rotation period. We also analyze the median spectrum with ZeeTurbo to derive the stellar parameters and estimate the small-scale magnetic field through Zeeman broadening. In addition, we perform Zeeman-Doppler Imaging of the LSD Stokes I and V profiles from the three observing seasons to reconstruct the surface brightness and large-scale magnetic maps, as well as to probe the small-scale field. Our preliminary analysis suggests that the magnetic topology evolves over the three seasons.We further analyze the radial velocities to assess the possible presence of a close-in planetary companion. The current results suggest that the observed RV variability is predominantly driven by stellar activity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.