If a star has a parallax of 0.05", then its distance in light-years is about:
A)6.4 light-years.
B)12.7 light-years.
C)20 light-years.
D)65 light-years.
E)100 light-years.

Question

Quizplus · Accepted Answer

The distance to a star in parsecs is the inverse of its parallax angle in arcseconds. A parallax of 0.05" corresponds to a distance of 1/0.05 = 20 parsecs. Since 1 parsec is approximately 3.26 light-years, the distance is 20 * 3.26 = 65.2 light-years, which is closest to 65 light-years.

If a Star Has a Parallax of 0