Exoplanet Detection by Astrometric Method

Abstract

As we known, the exoplanets are mostly detected by the methods of radial velocity and transit, only one is found by the astrometric method. As the data of the gaia to be released, astrometry will become one of the most important method for detecting exoplanets gradually. Based on the position sequence of stars, this paper discusses the calculation of the equations of dynamics conditions involved in solving the mass and the orbit parameters of the planet. Due to the deficiency of the available theory (orbital element method), we put forward a new method (coordinate velocity method). The differential correction formulae of the two methods are presented, as well as the necessary simulation. In addition, the method established in this paper can be applied to the multi-planet system easily.