We use high dynamic range, high-resolution L-band spectroscopy to measure the radial velocity variations of the hot Jupiter in the tau Bootis planetary system. The detection of an exoplanet by the shift in the stellar spectrum alone provides a measur
e of the planets minimum mass, with the true mass degenerate with the unknown orbital inclination. Treating the tau Boo system as a high flux ratio double-lined spectroscopic binary permits the direct measurement of the planets true mass as well as its atmospheric properties. After removing telluric absorption and cross-correlating with a model planetary spectrum dominated by water opacity, we measure a 6-sigma detection of the planet at K_p = 111 +- 5 km/s, with a 1-sigma upper limit on the spectroscopic flux ratio of 10^-4. This radial velocity leads to a planetary orbital inclination of i = 45+3-4degrees and a mass of M_P = 5.90+0.35-0.20 M_ Jup. We report the first detection of water vapor in the atmosphere of a non-transiting hot Jupiter, tau Boo b.
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 c
ombined with the inclination, i=90.3401+0.0016-0.0019 deg, measured from the Kepler photometric data by Doyle et al. 2011, we derive dynamical masses for the Kepler-16 components of M_A=0.654+-0.017 M_sun and M_B=0.1959+-0.0031 M_sun, a precision of 2.5% and 1.5% respectively. Our results confirm at the ~2% level the mass-ratio derived by Doyle et al. with their photometric-dynamical model, 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 photometric-dynamical modeling technique.
