Asteroseismology of hot subdwarf B stars observed with TESS: discovery of two new gravity mode pulsating stars [SSA]

http://arxiv.org/abs/2212.02950


TIC033834484 and TIC309658435 are long-period pulsating subdwarf B star, which were observed extensively (675 and 621 days, respectively) by the Transiting Exoplanet Survey Satellite (TESS).
The high-precision photometric light curve reveals the presence of more than 40 pulsation modes including both stars.
All the oscillation frequencies that we found are associated with gravity (g)-mode pulsations, with frequencies spanning from 80 $\mu$Hz (2 500 s) to 400 $\mu$Hz (12 000 s).
We utilize the asteroseismic tools including asymptotic period spacings and rotational frequency multiplets in order to identify the pulsational modes.
We found dipole (l = 1) mode sequences for both targets and calculate the mean period spacing of dipole modes ($\Delta P_{l=1}$), which allows us to identify the modes.
Frequency multiplets provide a rotation period of about 64 d for TIC033834484.
From follow-up ground-based spectroscopy, we find that TIC\,033834484 has an effective temperature of 24 210 K (140), a surface gravity of logg = 5.28 (03) and TIC309658435 has an effective temperature of 25 910 K (150), a surface gravity of logg = 5.48 (03).

Read this paper on arXiv…

M. Uzundag, R. Silvotti, A. Baran, et. al.
Wed, 7 Dec 22
51/74

Comments: Proceedings of the 10th International Conference on hot subdwarfs and related objects in Liege. arXiv admin note: text overlap with arXiv:2105.15137. text overlap with arXiv:2105.15137