Asteroseismology of TESS Luminaries in the PLATO era

Résumé fourni par la source

The NASA Transiting Exoplanets Survey Satellite (TESS) is delivering high-precision photometry for millions of stars. The upcoming PLAnetary Transits and Oscillations of stars mission (PLATO) will push this frontier even further, providing long-duration, high-precision observations of tens of thousands of bright stars to be characterised through asteroseismology. At the heart of PLATO lies a fully automated seismic pipeline, a first of its kind, designed to systematically extract oscillation frequencies across an unprecedented stellar sample. To ensure its reliability, well-characterised reference stars spanning a wide range of physical properties are essential. In this presentation, I have discussed the asteroseismic characterisation of 32 main-sequence and subgiant stars from the TESS Luminaries sample, including 26 stars analysed here for the first time. The targets span effective temperatures between approximately 5300 and 6900 K and exhibit a range of oscillation patterns representative of the stellar populations expected in PLATO long-duration observations. Using TESS data through Sector 88, we analyse the targets with three independent seismic pipelines employing different strategies for mode identification and peak-bagging optimisation. The comparison enables us to assess the robustness and consistency of extracted oscillation parameters, including mode frequencies, amplitudes, and linewidths, as well as the sensitivity of the results to methodological choices. Particular attention iss given to subgiant stars, where mixed-mode identification remains challenging in TESS-length time series and can lead to significant pipeline-to-pipeline differences in mode classification and fitted parameters. Overall, the independently derived seismic solutions show good agreement for the majority of targets, demonstrating the capability of TESS to provide high-quality seismic constraints for main-sequence and subgiant stars. At the same time, the comparison highlights current limitations in automated analyses, especially for evolved targets with complex mode spectra, and provides insight into the level of consistency that can be expected across different fitting approaches.

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