Short-period pulsating hot-subdwarf stars observed by TESS in Sectors 61 – 97

Abstract

We present results of a continuation of the search, started by Baran et al. (2023, 2024), for short-period pulsations in compact stellar objects observed during Sectors 61 – 97 of the TESS mission. We use newly collected and other unpublished spectroscopic data to confirm or determine spectral classification of many stars included in this work. From the TESS photometry, we identify 36 short-period hot-subdwarf pulsators, including 33 pulsators not known before the TESS mission. We present the results in a similar way to Baran et al. (2024). We provide an update on the instability strip and the evolutionary status of hot subdwarf stars with a more populated Kiel diagram. We discuss hybrid candidates as well as the results of testing correlations between theoretical predictions of the highest amplitude pulsation modes and spectroscopic parameters of stars found to be pressure-mode (p-mode) pulsators in the TESS mission. We report the discovery of the first p-mode dominated V366Aqr – type star, the first helium-enhanced hot subdwarf pulsator, and an unusual blue large-amplitude pulsator. We revise a classification of a previously reported BLAP star and correct the final TESS p-mode star statistics by accounting for a new spectral classification of two hot subdwarfs.