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)

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 =

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

Since p = 0.5 arcsec, then;

d =

  =

  = 2

d = 2 pc

The star is 2 parsec away from the earth.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.