太阳系质心加速度的确定及其对ICRS的影响  

The Acceleration of the Barycenter of Solar System Obtained from VLBI Observations and Its Impact on the ICRS

作　　者：徐明辉[1] 

机构地区：[1]中国科学院上海天文台,上海200030

出　　处：《天文学报》2016年第2期252-254,共3页Acta Astronomica Sinica

摘　　要：自1998年1月1日开始,国际天球参考系由一组遥远的射电源实现,取代了传统的恒星参考架.河外源的距离在亿光年尺度,实现了在空间固定的天球参考架.光行差效应由观测者的运动引起,与天体的距离无关.由于太阳系质心在空间的运动存在着微小的加速度,该加速度引起长期光行差发生漂移,使得在太阳系质心处观测到的河外射电源的位置有长期的偏折.空间固定的参考架为该观测现象提供了观测资料,进而可以确定太阳系质心在空间的运动加速度.Since 1998 January 1, instead of the traditional stellar reference system, the Interna- tional Celestial Reference System （ICRS） has been realized by an ensemble of extragalactic radio sources that are located at hundreds of millions of light years away （if we accept their cosmological distances）, so that the reference frame realized by extragalactic radio sources is assumed to be space-fixed. The acceleration of the barycenter of solar system （SSB）, which is the origin of the ICRS, gives rise to a systematical variation in the directions of the observed radio sources. This phenomenon is called the secular aberration drift. As a result, the extragalactic reference frame fixed to the space provides a reference standard for detecting the secular aberration drift, and the acceleration of the barycenter with respect to the space can be determined from the observations of extragalactic radio sources.

关 键 词：太阳系质心 ICRS 长期光行差 天球参考系 射电源 观测者 河外 视差动 观测资料 acceleration 

分 类 号：P185[天文地球—天文学]