Stellar Parallax

Stellar parallax is the apparent shift in the position of a nearby star against the background of distant stars, caused by Earth's movement around the Sun. As Earth orbits, our vantage point changes, making the star seem to wobble slightly. By measuring this tiny shift over six months, astronomers can calculate the star's distance. It’s similar to holding out your finger and alternately closing each eye—the finger appears to move against the background; the closer it is, the more it seems to shift. Stellar parallax is fundamental for determining the distances to stars nearby our solar system.