[1409.4774] Barycentric Corrections at 1 cm/s for precise Doppler velocities # Barycentric Corrections at 1 cm/s for precise Doppler velocities J. T. Wright11affiliation: Center for Exoplanets and Habitable Worlds, 525 Davey Lab, The Pennsylvania State University, University Park, PA, 16802 22affiliation: Department of Astronomy & Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA, 16802 ,J. D. Eastman33affiliation: Las Cumbres Observatory Global Telescope, 6740 Cortona Dr, Goleta, CA, 93117, USA 44affiliation: Department of Physics, Broida Hall, University of California Santa Barbara, Santa Barbara, CA, 93117, USA ###### Abstract The goal of this paper is to establish the requirements of a barycentric correction with an RMS of $\lesssim 1$ cm/s, which is an order of magnitude better than necessary for the Doppler detection of true Earth analogs ( $\sim 9$ cm/s). We describe the theory and implementation of accounting for the effects on precise Doppler measurements of motion of the telescope through space, primarily from rotational and orbital motion of the Earth, and the motion of the solar system with respect to target star (i.e. the “barycent