Question

What is parallax?

A) distance to an object, measured in parsecs
B) angle taken up by the size (e.g., diameter) of an object, as seen by an observer
C) shift in angular position of an object as it moves in space
D) apparent shift in position of an object as the observer moves

Answer 1

Parallax is the apparent shift in position of an object as the observer moves. It is used in astronomy to measure the distance to nearby stars.

Step-by-step explanation:

Parallax is the apparent shift in position of an object as the observer moves. In astronomy, parallax is used to measure the distance to nearby stars. It is defined as one-half the angle that a star shifts when seen from opposite sides of Earth's orbit. The smaller the parallax, the more distant the object being measured is.