Question

Suppose you measure the parallax angle for a particular star to be 0.1 arcsecond. The distance to this star is
A) 10 light-years.B) 10 parsecs.C) 0.1 light-year.D) 0.1 parsec.E) impossible to determine.

Answer 1

Answer:

B) 10 parsecs

Explanation:

The distance of a star measured with the parallax method is given by:

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

where

d is the distance, in Parsec

$\theta$ is the parallax angle, in arcseconds

For the star in the problem, the parallax angle is

$\theta=0.1''$

therefore, the distance of the star is

$d=\frac{1}{0.1''}=10 pc$

so, 10 parsecs.