A Keck/HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs
  We present results from our ongoing spectroscopic search for giant planets within 1 AU around a well-defined sample of metal-poor stars with HIRES on the Keck 1 telescope. We have achieved an rms radial velocity precision of $\sim 8$ m/s over a time-span of 1.5 years. The data collected so far build toward evidence of the absence of very short-period ($< 1$ month) giant planets. However, about 7% of the stars in our sample exhibits velocity trends indicative of the existence of companions. We place preliminary upper limits on the detectable companion mass as a function of orbital period, and compare them with the performance of ESA's future space-borne high-precision astrometric observatory Gaia. 
A. Sozzetti (1,2), D. W. Latham (2), G. Torres (2), R. P. Stefanik   (2), A. P. Boss (3), B. W. Carney (4), and J. B. Laird ...