GAIA计划与微角秒天体测量学

GAIA Project and Micr-earcsecond Astrometry

欧洲空间局正在考虑的空间天体测量卫星计划（GAIA计划）将对目视星等V亮于15．5mag的5千万颗目标进行位置、自行和视差的测定，其精度为10μas，同时还对这些目标进行多色多历元光度测定．该计划可对星系距离尺度、恒星演化、银河系运动学和动力学以及参考架联结等方面进行深入研究．其开创的微角秒天体测量学亦将会对天体物理学、太阳系天体和参考架联结等方面的研究产生深远的影响．

The 'Global Astrometric Interferometer for Astrophysics, GAlA' project, which is beingconsidered in the ESA, will observe 50 million stars brighter than 15.5mag, and get the data ofpositions, proper motions and parallaxes with the precision of 10μas, along with multi -colour,multi-epoch photometry for these objects. The scientific results of the project will be used to probedeeply in many fields of astronomy, such as galaxy distance scale, stellar evolution, kinematicsand dynamics of Galaxy, linkage among the optical reference frames and dynamical referenceframes and extragalactic reference frames. Therefore, the micro-arcsecond astrometry will becontributed possibly to the developments of the study in the astrophysics, solar system objectsand the linkage of reference frames.