The spectroscopic orbit of the planetary companion transiting HD 209458

We report a spectroscopic orbit with period P = 3.52433 +/- 0.00027 days fo r the planetary companion that transits the solar-type star HD 209458. For the metallicity, mass, and radius of the star, we derive [Fe/H] = 0.00 +/- 0.02, M* = 1.1 +/- 0.1 M-circle dot, and R* = 1.2 +/- 0.1 R-circle dot. Thi s is based on a new analysis of the iron lines in our HIRES template spectr um and also on the absolute magnitude, effective temperature, and color of the star, and it uses isochrones from four different sets of stellar evolut ion models. Using these values for the stellar parameters, we reanalyze the transit data and derive an orbital inclination of i = 86 degrees.1 +/- 1 d egrees.6. For the planet, we derive a mass of M-p = 0.69 +/- 0.05 M-Jup, a radius of R-p = 1.40 +/- 0.17 R-Jup, and a density of rho = 0.31 +/- 0.07 g cm(-3).