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 to the background stars.

Question

Quizplus · Accepted Answer

The proper motion of a star or other celestial object is determined by observing its movement across the sky relative to more distant background stars over time. This method does not involve measuring light intensity, Doppler shifts, or changes in angular diameter, but rather tracks the object's position.

The Proper Motion of a Star or Other Object Is