Stellar Wobble Due to a Nearby Binary System

To date, there are several reported exoplanet detections within binary star systems. These findings are based on radial velocity data for the target star. However, the companion star could in turn have a companion of which we are not aware. We describe how this hidden binary system affects the radial velocity of the target star, mimicking a planet in some circumstances We also explain what can be done in practice in order to distinguish between these two effects.