Spectropolarimetric snapshots of FGKM stars in the PLATO fields

Résumé fourni par la source

Magnetic activity plays a central role in the evolution of solar-type stars and in the environment of their exoplanets. Despite decades of study, detailed mapping of surface magnetic fields in stars suitable for asteroseismic investigations remains limited. To address this limitation, we have launched a dedicated spectropolarimetric campaign targeting a selection of FGKM stars, chosen for their spectral type, relevance for magnetic activity studies, and complementarity with future asteroseismic studies, in the PLATO field. Observations were obtained with Neo-Narval at the Telescope Bernard Lyot (TBL), ESPaDOnS and SPIRou at the Canada-France-Hawaii Telescope (CFHT) and HARPSpol at the European Southern Observatory (ESO), aiming to identify targets with detectable magnetic signatures suitable for long-term monitoring. Snapshot observations, with Neo-Narval and ESPaDOnS, have revealed to the detection of surface magnetic fields in several targets, showing that a fraction of PLATO stars exhibit detectable signatures suitable for Zeeman-Doppler Imaging (ZDI) follow-up. These detections provide an initial inventory of magnetically active FGKM stars in the PLATO fields and guide the selection of targets for long-term monitoring necessary to reconstruct their magnetic geometry. By focusing on stars that are accessible to both spectropolarimetry and PLATO photometry, this program demonstrates the feasibility of a targeted selection strategy and ground-based monitoring. This enables the combined exploration of the internal and surface manifestations of stellar dynamos. It highlights the complementarity between spectropolarimetric measurements and future asteroseismic observations, providing a robust foundation for systematic studies of stellar magnetism and the evolution of magnetic cycles in solar-type stars.

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