THE PHYSICAL PARAMETERS OF THE RETIRED A STAR HD 185351

We report here an analysis of the physical stellar parameters of the giant star HD 185351 using Kepler short-cadence photometry, optical and near infrared interferometry from CHARA, and high-resolution spectroscopy. Asteroseismic oscillations detected in the Kepler short-cadence photometry combined with an effective temperature calculated from the interferometric angular diameter and bolometric flux yield a mean density rho(star) = 0.0130 +/- 0.0003 rho(circle dot) and surface gravity log g = 3.280+/-0.011. Combining the gravity and density we find R-star = 5.35 +/- 0.20 R-circle dot and M-star=1.99 +/- 0.23M(circle dot). The trigonometric parallax and CHARA angular diameter give a radius R-star = 4.97+/-0.07 R-circle dot. This smaller radius, when combined with the mean stellar density, corresponds to a stellar mass 1.60 +/- 0.08 M-circle dot, which is smaller than the asteroseismic mass by 1.6 sigma. We find that a larger mass is supported by the observation of mixed modes in our high-precision photometry, the spacing of which is consistent only for M-star greater than or similar to 1.8M(circle dot). Our various and independent mass measurements can be compared to the mass measured from interpolating the spectroscopic parameters onto stellar evolution models, which yields a model-based mass M-star, (model) = 1.87+/-0.07 M-circle dot. This mass agrees well with the asteroseismic value, but is 2.6 sigma higher than the mass from the combination of asteroseismology and interferometry. The discrepancy motivates future studies with a larger sample of giant stars. However, all of our mass measurements are consistent with HD 185351 having a mass in excess of 1.5M(circle dot).