Question

If a star is measured to have a parallax angle of 0.5 arcsec, how far away is the star? a. 2 ly b. 2 pc c. 0.5 pc (astronomy)

Answer 1

Answer:

2 pc

Explanation:

The parallax angle is the angle of the earth at different times in a year relative to a given closest star.

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

where p is the parallax angle, d is the distance between the earth and the star

Since p = 0.5 arcsec, then;

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

  = $\frac{1}{0.5}$

  = 2

d = 2 pc

The star is 2 parsec away from the earth.