A Tentative Solution To The Proper Motions Of The Two Open Clusters M35、NGC1664 Based On Their CCD Images

In recent years, using proper motions to investigate on cluster’s membership probability and its internal movement, the search for extraterrestrial planets and measuring the quality of the black hole at the center of the Milky Way galaxy have become a hot topic of kinematics on the galaxy and the universe. In the investigations of proper motions in clusters, open cluster M35 and NGC1664 are both important clusters of great research values.Their properties, such as richness and membership probability, are good experimental data to the verification of stellar evolution.Using UCAC4 catalog published by Zacharias et al. as the initial catalog, this thesis deals with the images of open clusters M35 and NGC1664 shot by 1 m telescope and 2.4m telescope at Yunnan Observatory in recent years. The data with an epoch interval of 5 years and 6 years, after searching and matching, it will be computed for relative proper motions by using high order constant model and geometric distortion model. Based on the analysis of position residual and the precision of relative proper motions, the author finds that geometric distortion model is not stable. The precision of the result derived by high order constant model is higher than that of result achieved by geometric distortion model. At the end of this thesis the author presents in total of 570 star’s relative proper motions for open clusters M35 and NGC1664 by using high order constant model fitting method. Among them, the median of the precision of relative proper motions for NGC1664 are estimated at 2.4mas/yr and2.5mas/yr in right ascension and declination, respectively. The median of the precision of relative proper motions for M35 are estimated at 1.6mas/yr and 1.9mas/yr in right ascension and declination, respectively. With comparison to Bouy et al.’s research on M35 cluster in2015, it reflects that the accuracy of M35 cluster’s proper motions solved in this thesis is better than the proper motions on UCAC4 catalog, whereas there is still some difference between our derived results and Bouy et al.’s work.