The proper motion of a star or other object is measured by:
A) measuring the intensity of the light in different regions of the blackbody curve.
B) observing the Doppler shift of spectral lines in the light from the object.
C) measuring the change in the angular diameter of the object.
D) watching the object move compared with the background stars.

Question

Quizplus · Accepted Answer

The proper motion of a star or other object is measured by watching the object move compared with the background stars. This motion is very small and is measured in arcseconds per year. This method of measurement is done through astrometry.

The Proper Motion of a Star or Other Object Is