A catalogue of A-F variable stars within PLATO's first field of view, LOPS2

Abstract

Space-based photometry has enabled major advances in asteroseismology, particularly for intermediate-mass A-F type stars located at the intersection of the main sequence and the classical instability strip. These stars, including δ Scuti, γ Dor, and roAp variables, exhibit a wide range of pulsation regimes and excitation mechanisms, but their large-scale characterisation is often limited by the absence of oscillation frequencies in most catalogues. We present the Survey of PLATO A-Type stars Oscillation frequencies (SPATO), a catalogue of stellar parameters and pulsation frequencies for A–F type stars in the PLATO Long-duration Observation Phase South (LOPS2), and assess the validity of classical classification schemes based on frequency domains. We homogeneously processed and analysed TESS light curves to extract independent frequencies. We combined stellar parameters from TESS and to define an enriched sample. We classified pulsators according to their frequency content. Gaia The classical separation at five cycles per day does not clearly distinguish between and stars in the HR diagram. Instead, the period–luminosity diagram reveals two main populations separated by a low-density region, which we propose as an alternative observational discriminator. Radial modes, particularly the fundamental and first overtones, follow well-defined relations, while higher overtones show larger dispersion. We find linear relations between the observational ν_ and estimates of the radius and surface gravity, which may help mitigate spectroscopic T_ -łog g degeneracies if calibrated against independent spectroscopy. eff The SPATO catalogue provides a large, homogeneous dataset that highlights the limitations of classical classifications and supports the use of period–luminosity relations as complementary tools, paving the way for future studies with PLATO.