KIC 9656397: Long-period, Extremely Short-eclipse Detached Eclipsing Binary with Pulsation?

We conducted a detailed study of the 700 day light curve of KIC 9656397. The target is a long-period detached eclipsing binary, exhibiting short eclipses and out-of-eclipse variations, and is reported to be a member of the open star cluster NGC 6811. We retrieved the light curve and spectra from the Kepler and LAMOST databases. We used PHOEBE to simulate the light curve and employ EMCEE to find the best-fitting physical parameters. The effective temperatures of the primary and secondary components are T p = 627 0 − 130 + 140 K and T s = 636 0 − 130 + 140 K, respectively. The mass ratio, orbital inclination, and eccentricity are 1.0 0 − 0.10 + 0.10 , 89.84 0 − 0.001 + 0.001 deg, and 0.22 3 − 0.002 + 0.001 , respectively. We also derived absolute masses, radii, and luminosities of the two components, which are: M p = 1.1 5 − 0.09 + 0.15 M ⊙ , M s = 1.1 6 − 0.14 + 0.19 M ⊙ , R p = 1.0 <mm