THE SDSS-HET SURVEY OF KEPLER ECLIPSING BINARIES: SPECTROSCOPIC DYNAMICAL MASSES OF THE KEPLER-16 CIRCUMBINARY PLANET HOSTS

We have used high-resolution spectroscopy to observe the Kepler-16 eclipsing binary as a double-lined system and measure precise radial velocities for both stellar components. These velocities yield a dynamical mass ratio of q = 0.2994 +/- 0.0031. When combined with the inclination, i = 90.degrees 3401(-0.0019)(+0.0016), measured from the Kepler photometric data by Doyle et al. (D11), we derive dynamical masses for the Kepler-16 components of M-A = 0.654 +/- 0.017 M-circle dot and M-B = 0.1959 +/- 0.0031 M-circle dot, a precision of 2.5% and 1.5%, respectively. Our results confirm at the similar to 2% level the mass-ratio derived by D11 with their photometric-dynamical model (PDM), q = 0.2937 +/- 0.0006. These are among the most precise spectroscopic dynamical masses ever measured for low-mass stars and provide an important direct test of the results from the PDM technique.