V456 Cyg: An eclipsing binary with tidally perturbed <i>g</i>-mode pulsations

Context. Many well-known bright stars have been observed by the ongoing Transiting Exoplanet Survey Satellite (TESS) space mission. For several of them, these new data reveal previously unobserved variability, such as tidally perturbed pulsations in close binary stars. Aims. Using newly detected gravity-mode (g-mode) V456 Cyg, we aim to determine global stellar properties this short-period eclipsing and evaluate interaction between tides. Methods. We model orbit physical component using TESS photometry published spectroscopy. then measure pulsation frequencies from residuals light curve fit iterative prewhitening, analyse them asteroseismic parameters. parameters a function orbital phase. Results. find that belong secondary Cyg star likely has uniform radial rotation profile, synchronous ($\nu_{\rm rot} = 1.113(14) \rm d^{-1}$) with orb} 1.122091(8) d^{-1}$). The g modes are amplified almost factor three hemisphere facing primary. present evidence is caused tidal perturbation pulsations, mode coupling being strongly affected. Conclusions. only second object for which high-order g-mode identified, after $\pi^5$ Ori. This opens up opportunities asteroseismology, it demonstrates another avenue tides can interact each other.