How would you use the parallax formula to determine the distances to a star (in parsecs)? The parallax angle is 0.0012516.

1 Answer
Oct 11, 2016



The angle has to be in second ( '' ) unit.

For 1'' parallax angle, the distance is 1 parsec.

For other values in seconds, the distance = 1/(angle in seconds)

parsecs. This is for approximations, for a few significant digits (sd)


Here, the distance is 1 /.0012516 = 798.98 parsecs, nearly.

Had the unit of the angle been taken as degree,

the distance ( 0222 parsec ) will be too small to be the distance

of a star.

The distance of the nearest star Proxima Centauri is 1.293 parsecs.