Asteroseismology of PG 1541$+$651 and BPM 31594 with TESS

TL;DR

This study uses TESS photometry to detect multiple pulsation periods in two ZZ Ceti stars, enabling detailed asteroseismological modeling and rotation period estimation, improving understanding of their internal structures.

Contribution

First detailed asteroseismological analysis of PG 1541+651 and BPM 31594 using TESS data, revealing multiple pulsation modes and rotation periods.

Findings

Detected 12 and 6 pulsation periods in PG 1541+651 and BPM 31594, respectively.

Estimated stellar masses around 0.61 solar masses with thick hydrogen envelopes.

Derived rotation periods of approximately 22 hours and 11.6 hours for the two stars.

Abstract

We present the photometric data from TESS for two known ZZ Ceti stars, PG 1541+651 and BPM 31594. Before TESS, both objects only had observations from short runs from ground-based facilities, with three and one period detected, respectively. The TESS data allowed the detection of multiple periodicities, 12 for PG 1541$+$651, and six for BPM 31594, which enables us to perform a detailed asteroseismological study. For both objects we found a representative asteroseismic model with canonical stellar mass ~ 0.61 Msun and thick hydrogen envelopes, thicker than 10^(-5.3) M_*. The detection of triplets in the Fourier transform also allowed us to estimate mean rotation periods, being ~22 h for PG 1541+651 and 11.6 h for BPM 31594, which is consistent with range of values reported for other ZZ Ceti stars.