We present Kepler photometry and ground based spectroscopy of KIC 4544587 , a short-period eccentric eclipsing binary system with self-excited pressure and gravity modes , tidally excited modes , tidally influenced p modes , and rapid apsidal motion of 182 y per cycle .
The primary and secondary components of KIC 4544587 reside within the \delta Scuti and \gamma Dor instability region of the Hurtzsprung-Russell diagram , respectively .
By applying the binary modelling software phoebe to prewhitened Kepler photometric data and radial velocity data obtained using the William Herschel Telescope and 4-m Mayall telescope at KPNO , the fundamental parameters of this important system have been determined , including the stellar masses , 1.98 \pm 0.07 \ > { M _ { \odot } } and 1.60 \pm 0.06 \ > { M _ { \odot } } , and radii , 1.76 \pm 0.03 R _ { \odot } and 1.42 \pm 0.02 R _ { \odot } , for the primary and secondary components , respectively .
Frequency analysis of the residual data revealed 31 modes , 14 in the gravity mode region and 17 in the pressure mode region .
Of the 14 gravity modes 8 are orbital harmonics : a signature of tidal resonance .
While the measured amplitude of these modes may be partially attributed to residual signal from binary model subtraction , we demonstrate through consideration of the folded light curve that these frequencies do infact correspond to tidally excited pulsations .
Furthermore , we present an echelle diagram of the pressure mode frequency region ( modulo the orbital frequency ) and demonstrate that the tides are also influencing the p modes .
A first look at asteroseismology hints that the secondary component is responsible for the p modes , which is contrary to our expectation that the hotter star should pulsate in higher radial overtone , higher frequency p modes .