ABSOLUTE STELLAR PARAMETERS OF KIC 09246715: A DOUBLE-GIANT ECLIPSING SYSTEM WITH A SOLAR-LIKE OSCILLATOR

We present our results of a combined analysis of radial velocity and light curves (LCs) of a double-lined spectroscopic and eclipsing binary KIC 09246715, observed photometrically by the Kepler satellite and spectroscopically with the OAO-1.88 m telescope with the HIgh-Dispersion Echelle Spectrograph. The target was claimed to be composed of two red giants, one of which is showing solar-like oscillations. We have found that the mass and radius of the primary are M-1 = 2.169 +/- 0.024 M-circle dot and R-1 = 8.47 +/- 0.13 R-circle dot, and of the secondary are M-2 = 2.143 +/- 0.025 M-circle dot and R-2 = 8.18 +/- 0.09 R-circle dot, which confirms their double-giant status. Our secondary is the star to which the oscillations were attributed. Results of its previous asteroseismic analysis are in agreement with ours, only significantly less precise, but the subsequent LC-based study failed to derive the correct mass and radius of our primary. KIC 09246715 is one of the rare cases where asteroseismic parameters of a solar-like oscillator were confirmed by an independent method and only the third example of a Galactic double-giant eclipsing binary with masses and radii measured with precision below 2%.