Question

The effect of parallax is used to measure:

• A. distances to nearby objects
• B. distances to nearby stars
• C. nearness of atoms in substances
• D. the object and image distance in optical experiments

Answer 1

The correct option is B distances to nearby stars

Astronomers use an effect called parallax to measure distances to nearby stars. Parallax is the apparent displacement of an object because of a change in the observer's point of view.

As the Earth orbits the sun, a nearby star will appear to move against the more distant background stars. Astronomers can measure a star's position once, and then again 6 months later and calculate the apparent change in position.