A search for variable subdwarf B stars in TESS Full Frame Images III. An update on variable targets in both ecliptic hemispheres -- contamination analysis and new sdB pulsators

TL;DR

This study updates the catalog of variable subdwarf B stars using TESS full frame images, identifying false positives, clarifying variability status, and discovering new pulsators through contamination analysis and spectroscopic classification.

Contribution

It provides an updated analysis of variable stars in TESS data, including contamination correction and the discovery of 11 new sdB pulsators, enhancing the understanding of these stars.

Findings

Identified 1,403 variable stars from 2,995 targets.

Discovered 11 new sdB pulsators.

Clarified variability status of targets with contamination analysis.

Abstract

We present an update on the variable star survey performed on the TESS 30 min Full Frame Image (FFI) data reported by our first two papers in this series. This update includes a contamination analysis in order to identify false positives and analysis of the TESS 10 min FFI data collected during Years 3 and 4 of the mission. We clarify the variability status of 2 995 targets identifying 1 403 variable stars. In addition, we spectroscopically classify 24 pre-filtered targets sampled with the 10 min FFI data and discover 11 new sdB pulsators. Future follow-up space- and/or ground-based data of variables reported here, to identify the nature of their variability and reveal spectroscopic parameters of the stars, would complement this work.