  We present a detailed study of KIC 2306740, an eccentric double-lined
eclipsing binary system. Kepler satellite data were combined with spectroscopic
data obtained with the 4.2 m William Herschel Telescope (WHT). This allowed us
to determine precise orbital and physical parameters of this relatively long
period (P=10.3 d) and slightly eccentric, ($e=0.3$) binary system. The physical
parameters have been determined as $M_1 = 1.194\pm0.008$ M$_{\odot}$, $M_2 =
1.078\pm0.007$ M$_{\odot}$, $R_1 = 1.682\pm0.004$ R$_{\odot}$, $R_2 =
1.226\pm0.005$ R$_{\odot}$, $L_1 = 2.8\pm0.4$ L$_{\odot}$, $L_2 = 1.8\pm0.2$
L$_{\odot}$ and orbital seperation $a = 26.20\pm0.04$ R$_{\odot}$ through
simultaneous solutions of Kepler light curves and of the WHT radial velocity
data. Binarity effects were extracted from the light curve in order to study
intrinsic variations in the residuals. Five significant and more than
100~combination frequencies were detected. We modeled the binary system
assuming non-conservative evolution models with the Cambridge STARS (TWIN) code
and we show evolutionary tracks of the components in the $\log L - \log T$
plane, the $\log R - \log M$ plane and the $\log P - \rm age$ plane for both
spin and orbital periods together with eccentricity $e$ and $\log R_1$. The
model of the non-conservative processes in the code led the system to evolve to
the observed system parameters in roughly $5.1 $ Gyr.

Solar and Stellar Astrophysics