A Study on the Kinematics of Hierarchical Triple Stars

Our statistical analysis shows that, because of the three-body effects, the classical double two-body model cannot be used to describe the kinematics of most hierarchical triple star systems with the precision of present day observations (1 mas). Even for the usual practical requirements, this model is not suitable for figuring those systems suffering significant three-body effects. Because it is not practical to use numerical ephemerides with a large volume of data to describe the kinematics of component stars in a star catalogue, a kinematical model as simple and practical as possible for the hierarchical triple star systems is needed. Based on the existing observations and their associated fitting results, we obtain consistent mass parameters and initial conditions of six hierarchical triple star systems. Then the description of the kinematics of these systems on the basis of practical requirements is discussed.