Characterizing bright $\delta$ Scuti pulsators using TESS lightcurves

TL;DR

This study analyzes bright, young delta Scuti stars using TESS and Gaia data, identifying pulsators, their distribution, and associations, providing insights into their pulsation modes and evolutionary status.

Contribution

It offers the first large-scale characterization of bright delta Scuti stars near the zero-age main sequence with detailed pulsation and membership analysis.

Findings

Identified 444 delta Scuti pulsators from 2041 stars.

Pulsator fraction peaks at ~70% within the instability strip.

Detected low-frequency pulsators with potential mixed modes.

Abstract

We present a study of bright, young $\delta$ 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 $\delta$ 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 $\delta$ Scuti stars from our sample are association members.