High-Resolution Spectroscopy of the Planetary Host HD 13189:   Highly-Evolved and Metal-Poor
  We report on the abundances of 13 elements in the planetary host HD 13189, a massive giant star. Abundances are found to be sub-solar, with [Fe/H] = -0.58 +/- 0.04$; HD 13189 is one of the most metal-poor planetary hosts yet discovered. Abundance ratios relative to Fe show no peculiarities with respect to random field stars. A census of metallicities of the seven currently known planet-harboring giants results in a distribution that is more metal-poor than the well-known metal-rich distribution of main sequence (MS) planetary hosts. This finding is discussed in terms of accretion of H-depleted material, one of the possible mechanisms responsible for the high-metallicity distribution of MS stars with planets. We estimate the mass of the HD 13189 progenitor to be 3.5 M_sun but cannot constrain this value to better than 2-6 M_sun. A stellar mass of 3.5 M_sun implies a planetary mass of m sin i = 14.0 +/- 0.8 M_J, placing the companion at the planet/brown dwarf boundary. Given its physical characteristics, the HD 13189 system is potentially unique among planetary systems, and its continued investigation should provide invaluable data to extrasolar planetary research. 
Simon C. Schuler (Clemson Univ.), James H. Kim (Boston Univ.), Michael   C. Tinker Jr.(Clemson Univ.), Jeremy R. King (Clems...