Investigating accreted star candidates using TESS survey

Abstract

. With the aim of exploring TESS metal-poor accreted star candidates, we calculated chemical abundances, dynamical properties, and ages of a sample of 30 stars. We found that our sample is dominated by metal-poor ([Fe/H] ≤ -0.7) old objects (ages ≥ 7 Gyrs), but we identified a fraction of apparently young objects (ages ≤ 7 Gyrs). The stars also have [ α /Fe] ≥ 0.2, and [Cu/Fe] ≤ 0. Finally, according to their dynamical properties, we concluded that the majority of our sample is composed of stars likely from the Gaia-Sausage-Enceladus progenitor (GES). Additionally, we explored the impact of incorporating asteroseismic information on age and chemical abundance calculations of metal-poor accreted stars for which <monospace>TESS</monospace> data is available. While we observe that the inclusion of seismic information significantly impacts the stellar ages obtained for our sample of stars, chemical abundances suffer a less significant effect in this study.