How does distance affect stellar parallax?

1 Answer
Dec 11, 2016

Inversely proportional to the distance.


The relation is parallax angle varies as the reciprocal of the


Smaller the angle, longer is the distance.

If parallax angle #alpha# radian is the angle between the

directions in which the same star is observed from the same place

on the Earth in a time-gap of 1/2 year, the distance of the star is

nearly #(2/alpha) AU#.

If the star is the ( nearest to us ) Sun, the distance 1 AU=(2/alpha)

AU. So, ^alpha = 2 radian = #114.6^o#, nearly. The next nearest to

us, Proxima Centauri is at a distance of 4.246 light years = 63242 X

4.246 AU= 268526 AU, nearly. This parallax angle ( measured in a

time gap of 1/2 year) will be 2/268526 radian = 0.00000745

radian = 1.5'', nearly.