English

Pulsating B stars in the Scorpius-Centaurus Association with TESS

Solar and Stellar Astrophysics 2026-02-18 v7

Abstract

We study 119 B stars located in the Scorpius-Centaurus Association using data from NASA's TESS Mission. We see pulsations in 81 stars (68%) across the full range of effective temperatures. In particular, we confirm previous reports of low-frequency pulsations in stars whose temperatures fall between the instability strips of SPB stars (slowly pulsating B stars) and δ\delta Scuti stars. By taking the stellar densities into account, we conclude that these cannot be p modes and confirm previous suggestions that these are probably rapidly-rotating SPB stars. We also confirm that they follow two period-luminosity relations that are consistent with prograde sectoral g modes that are dipole (l=m=1l=m=1) and quadrupole (l=m=2l=m=2), respectively. One of the stars (ξ2\xi^2 Cen) is a hybrid pulsator that shows regular spacings in both g and p modes. We confirm that α\alpha Cru has low-amplitude p-mode pulsations, making it one of the brightest β\beta Cephei stars in the sky. We also find several interesting binaries, including a very short-period heartbeat star (HD 132094), a previously unknown eclipsing binary (π\pi Lup), and an eclipsing binary with high-amplitude tidally driven pulsations (HR 5846). The results clearly demonstrate the power of TESS for studying variability in stellar associations.

Keywords

Cite

@article{arxiv.2203.02582,
  title  = {Pulsating B stars in the Scorpius-Centaurus Association with TESS},
  author = {Awshesh N. Sharma and Timothy R. Bedding and Hideyuki Saio and Timothy R. White},
  journal= {arXiv preprint arXiv:2203.02582},
  year   = {2026}
}

Comments

published by MNRAS; supplementary PDF with figures available at http://www.physics.usyd.edu.au/~bedding/sharma2022/