How does parallax change with distance?

1 Answer
Nov 26, 2015

Parallax is inversely proportional to the distance.


Stellar parallax can be defined as the apparent change in position of a nearby star against the background of more distant stars as the Earth orbits the Sun.

The formula to calculate stellar parallax is :

d = #1 / p#


d is the distance in parsecs
p is the parallax in arcsecs

so, parallax is inversely proportional to the distance, the greater the distance the smaller is the parallax.

consider a nearby Star, Proxima-Centauri, it is about 1.31 parsecs away, about 4.25 Light Years.

Its parallax can be given by,

p = #1/d#

p = #1/1.31#

p = #0.763# arcsecs