固こ有ゆう運うん動どう

noun

proper motion

Astronomical term for the apparent angular motion of a star across the sky, relative to more distant background objects.

• バーナード星せいは固こ有ゆう運うん動どうが非ひ常じょうに大おおきいことで知しられている。

  Barnard's Star is known for its very large proper motion.