Detection of gravity modes in the massive binary V380 Cyg from Kepler spacebased photometry and high-resolution spectroscopy

TL;DR

This study discovers gravity-mode oscillations in the massive binary V380 Cyg using high-quality Kepler photometry and spectroscopy, providing new insights into the star's internal physics and improving its orbital parameters.

Contribution

It is the first to detect gravity-mode oscillations in V380 Cyg, enhancing understanding of massive B-type star interiors through combined photometric and spectroscopic analysis.

Findings

Detection of gravity-mode oscillations in V380 Cyg

Improved orbital and fundamental parameters for the binary

Identification of line-profile variability in the primary star

Abstract

We report the discovery of low-amplitude gravity-mode oscillations in the massive binary star V380 Cyg, from 180 d of Kepler custom-aperture space photometry and 5 months of high-resolution high signal-to-noise spectroscopy. The new data are of unprecedented quality and allowed to improve the orbital and fundamental parameters for this binary. The orbital solution was subtracted from the photometric data and led to the detection of periodic intrinsic variability with frequencies of which some are multiples of the orbital frequency and others are not. Spectral disentangling allowed the detection of line-profile variability in the primary. With our discovery of intrinsic variability interpreted as gravity mode oscillations, V380 Cyg becomes an important laboratory for future seismic tuning of the near-core physics in massive B-type stars.