The Red Horizontal-Branch Star HD 17072

Abstract

We summarize the results of a spectroscopic analysis of HD 17072, finding it to be a metal-poor ([Fe/H] = -1.17) red horizontal-branch star with T_eff = 5375 K and log g = 2.4. We also derive a radial velocity of 62.8 km s^-1. It has the best determined Hipparcos trigonometric parallax among the metal-poor field horizontal-branch stars and supports the fainter luminosities for such stars found from statistical parallax and Baade-Wesselink analyses, in contradiction to the results of main-sequence fitting of metal-poor field dwarfs to globular cluster main sequences.