"Radial velocity" refers to the speed at which an object is moving directly towards or away from an observer. It is a measure of how quickly something is getting closer or further away from a specific point. Full definition
HARPS allows for measurements of radial velocities of stars, which can be affected by the presence of nearby planets, to be taken with the highest accuracy currently available. (sciencedaily.com)
We also used radial velocity measurements of the host star, spanning a time range of $ \ sim $ 30 yr, to constrain the companion's mass and orbital properties, as well as to probe the host star's spectral age indicators and general spectral energy distribution. (arxiv.org)
«The most important discovery in this work is that we have detected the weakest signal and are reaching the limit of detecting Earth analogs using radial velocity method,» Feng said. (gizmodo.com)