Question

A star's distance ($d$) and its parallax angle ($p$) are related to each other as:

• A. $d=\frac{1}{p}$
• B. $d=\frac{1}{p^2}$
• C. $p=\frac{1}{d^2}$
• D. none of these

Answer 1

The correct option is A $d=\frac{1}{p}$

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.

The relationship between a star's distance and its parallax angle:

$d=\frac{1}{p}$

The distance $d$ is measured in parsecs and the parallax angle $p$ is measured in arc seconds.