以河外星系为参考系的恒星自行测定现状

Present Situation on Determinations of Stellar Proper Motions with Respect to Extragalactic System

河外星系系统是准惯性系统。以河外星系为参考系测定的恒星自行对于研究银河系运动学和动力学演化,改进星系结构的模型,测定岁差常数改正和星表的系统差等都是十分重要的资料;对地面测量和空间天体测最的联系也是很有参考价值的。本文概要叙述了该工作目前的进展状况,较详细地介绍了美国Lick天文台的NPM计划,以及我们的看法。

The reference frame composed of extragalactic objects is a quasi-inertial reference frame. Stellar proper motions with respect to an extragalactic reference frame are a valuable database for many fields,such as studies on structure,kinematics and dynamics evolution of the Galaxy,improvment of the galactic structural model,and determinations of corrections to the constants of precession and of systematic error of fundamental catalogues, and establishment of connection between space-astroraetry and geo-astro-metry. This paper summarizes the present situation on this work, especially in detail for Lick NPM program, and our propositions to this work.