Rotation signature of TESS B-type stars. A comprehensive analysis

TL;DR

This study provides a comprehensive analysis of rotation periods in 160 TESS B-type stars using multiple techniques, identifying new rotational variables and clarifying variability sources, which aids stellar evolution modeling.

Contribution

It introduces a robust multi-method approach to detect stellar rotation in B-type stars and confirms or discovers rotation periods, improving understanding of stellar variability.

Findings

Rotational periods identified for 6 new TESS B-type stars.

Confirmed periodicities for 22 previously known targets.

Differentiated rotation from pulsation, binarity, and noise in light curves.

Abstract

Stellar rotation is a fundamental observable that drives different aspects of stellar and planetary evolution. In this work, we present an unprecedented manifold analysis of 160 B-type stars with light curves collected by the TESS space mission using three different procedures (Fast Fourier Transform, Lomb-Scargle, and wavelet techniques), accompanied by rigorous visual inspection in the search for rotation periodicities. This effort provides rotational periodicities for 6 new TESS B-type stars and confirmed periodicities for 22 targets with rotation periods previously listed in the literature. For other 61 stars, already classified as possible rotational variables, we identify noisy, pulsational, binarity, or ambiguous variability behavior rather than rotation signatures. The total sample of 28 potential rotators shows an overlap of different classes of rotational variables, composed of $\alpha^2$ Canum Venaticorum, rotating ellipsoidal and SX Arietis stars. The combination of the three techniques applied in our analysis offers a solid path to overcome the challenges in the discrimination of rotation from other variabilities in stellar light curves, such as pulsation, binarity or other effects that have no physical meaning. Finally, the rotational periodicities reported in the present study may represent important constraints for improving stellar evolution models with rotation, as well as asteroseismic studies of hot stars.