Characterizing bright $\hat{I}´$ Scuti pulsators using TESS lightcurves

Abstract

We present a study of bright, young $\hat{I}´$ Scuti stars near the zero-age main sequence using TESS light curves and Gaia DR3 data. From a sample of 2041 stars with G<7 and $G_{BP}-G_{RP}$ colour in the range 0-0.6, we identified 444 $\hat{I}´$ Scuti pulsators. We measured a pulsator fraction of ~70% in the middle of the instability strip, tapering off towards the edges. A period - luminosity diagram reveals a concentration along the fundamental mode and overtone ridges. We addressed sample completeness and identified low-frequency pulsators possibly exhibiting mixed modes. Cross-matching with nearby young associations showed that 63 $\hat{I}´$ Scuti stars from our sample are association members.

published in MNRAS