The recent detection of an exoplanet (Proxima b) around Proxima Centauri highlighted the increasing precision of extrinsic stellar radial velocity (vr) measurements. A thousand fold improvement (from ±1 km/s to ±1 m/s) has been achieved over the last few decades. While intrinsic stellar variability may set a "background" limit of ±1 m/s for cool stellar systems, the ultimate precision of a few decimeters/s (±1 - 2 dm/s) is the current goal of astronomical spectroscopists.
Increased precision also permitted a fundamental improvement to a crucial "rung" of the cosmic distance "ladder": high precision measurements of intrinsic (pulsation) radial velocities of galactic Cepheid variables (along with contemporaneous BVR photometry). The unique Cepheid period-luminosity-color (P-L-C) relation provides the crucial bridge in the distance scale from direct parallax to "standard candles" (Type Ia supernovae). The development of a second generation coudé radial velocity spectrometer (RVM), which provided the basis for an extensive Cepheid observing program, is described as well several unexpected discoveries, including the triple Cepheid system S Sagittae.