Labs / Astronomy
Parallax Distance Finder
As Earth swings from one side of its orbit to the other, a nearby star appears to slide back and forth against the far-off background. Drag Earth around its orbit and set the star's true distance — the tinier the wobble, the farther the star. The half-angle of that wobble, measured over a one-astronomical-unit baseline, is the parallax, and its distance in parsecs is simply 1 divided by that angle.
shift +0.000″p 0.379″base 0.00 AUd 2.64 pc8.6 ly
What to try
- Push the star out to 12 parsecs. What happens to the size of its apparent shift in the sky view?
- The parsec is defined by a parallax of exactly one arcsecond — at what distance does that happen here?
- If you could only measure angles down to 0.01″, how far away could you still reach with parallax?
- Why does the shift shrink to zero when Earth is at the top or bottom of its orbit, and peak at the sides?
- Proxima Centauri and Vega are both preset here — how many times larger is Proxima's parallax angle?