A star with an observed parallax of 0.2 arcseconds is 5 parsecs away from the observer. The distance to an object is inversely proportional to the magnitude of its stellar parallax, which means the smaller the change in its apparent position, the further away it is.
To obtain a distance from measuring the parallax shift of a star is a relatively simple equation: d=1/P. This means that the distance (in parsecs) is equal to 1 divided by the number of arcseconds in the parallax. Therefore, if a star has an observed parallax shift of 0.2, the equation is as follows: d=1/0.2; d = 5 parsecs.