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

2 pc

Step-by-step explanation:

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

P =
`(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 =
`(1)/(p)`

=
`(1)/(0.5)`

= 2

d = 2 pc

The star is 2 parsec away from the earth.