Short-period pulsating hot subdwarf stars observed by TESS

0586748 - ASÚ 2025 RIV FR eng J - Journal Article
Baran, A.S. - Charpinet, S. - Ostensen, R. - Reed, M. D. - Van Grootel, V. - Lyu, C. - Telting, J. H. - Németh, Péter
Short-period pulsating hot subdwarf stars observed by TESS.
Astronomy & Astrophysics. Roč. 686, Jine (2024), č. článku A65. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR(CZ) GA22-34467S
Institutional support: RVO:67985815
Keywords : stars * oscillations * solar and stellar astrophysics
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.5, year: 2022
Method of publishing: Open access

We present the results of an extension of our Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed during the second and fourth years of the TESS mission, which targeted the northern ecliptic hemisphere. For many of the targets, we exploited unpublished spectroscopic data to confirm or re-evaluate the object's spectral classification. From the TESS photometry, we identified 50 short-period hot-subdwarf pulsators, including 35 sdB and 15 sdOB stars. The sample contains 26 pulsators that were unknown prior to the TESS mission. Nine stars show signals at both low and high frequencies and have been categorized as hybrid pulsators. For each pulsator, we report the list of prewhitened frequencies, along with and their amplitude spectra calculated from the TESS data. We attempt to identify possible multiplets caused by stellar rotation and we report five candidates with rotation periods between 11 and 46 d. With the search for p-mode pulsating hot subdwarfs in TESS Sectors 1-60 complete, we discuss the completeness of the study, as well as the instability strip and the evolutionary status of the stars we found. We also compare the distribution of pulsation periods as a function of effective temperature and surface gravity with theoretical predictions.
Permanent Link: https://hdl.handle.net/11104/0354191