What is Parallax?

Parallax is a way astronomers measure the distance to stars. It's based on a simple idea: if you hold your finger up close to your face and look at it with one eye closed, then the other, your finger appears to shift against the background. The closer your finger is, the more it shifts.

The same principle applies to stars. Astronomers observe a star from two different points in Earth's orbit (usually six months apart) and measure the tiny shift in the star's position against the distant background of stars. The larger the shift (parallax), the closer the star.

If One Star's Parallax is Ten Times Larger

If one star has a parallax ten times larger than another star, it means the first star is ten times closer to Earth.

Why?

Parallax is inversely proportional to distance. This means that:

* A larger parallax indicates a smaller distance.

* A smaller parallax indicates a larger distance.

In Summary

A star with a ten times larger parallax is much closer to us than a star with a smaller parallax.