32 naked-eye stars seismic characterisation

Individual mode parameters were extracted using three independent seismic pipelines, one of which was similar to the algorithms used in the official PLATO pipeline. The Peirce criterion and a Z-score were applied to identify the optimal combination of data calibration, observing cadence, and fitting pipeline for each star. We analyse 32 MS and SG stars up to TESS Sector 88, with individual mode frequencies derived for the first time for 26 of them.

For all stars, we derived large and small separations, the asymptotic phase term epsilon, radial mode amplitudes, and mean linewidths per order. Comparisons with previous Kepler observations reveal consistent trends in the seismic parameters, confirming the robustness of our analysis based on TESS data. In sub-giants, mixed-mode identification differs in the three pipelines, revealing extraction inconsistencies requiring longer datasets to improve our mode identifications.

These results demonstrate the capability of TESS to deliver high-quality asteroseismic observations for MS and SG stars. The Luminaries stars located in the PLATO LOP fields constitute a unique sample that will play a crucial role in validating, calibrating, and optimising PLATO's seismic performance from the earliest stages of the mission.