proper motion

• n. [天]自行；天体之固有运动

proper motion的用法和样例：

例句

用作名词 (n.)

1. Risk the illegal website proper motion that establishs with stockjobber name to shut.
   冒用证券公司名义设立的非法网站自行关闭。
2. However, if its membership can be confirmed by proper motion and radial velocity determinations, the cause of light variation may not be pulsation.
   但是，如果自行或视线速度测定证实为其成员星，那么变光的原因也许不是脉动。