Question

What is proper motion? A) It is the annual apparent motion of a star across the sky. B) It is the true, not apparent, motion of a star in space. C) It is the orbital motion of a star around the Galaxy. D) It is the motion of a star towards or away from us, revealed by Doppler shifts. E) It is the apparent shift as we go to opposite sides of our orbit every six months.

Answer 1

Answer: A

Step-by-step explanation:

Proper Motion is the apparent angular motion of a star across the sky with respect to more distant stars. Typical proper motion is ~0.1 arcsec/year