Here's how it works:
1. Observation: We observe the star from two different points in Earth's orbit, six months apart. This creates a baseline of roughly 300 million kilometers (186 million miles).
2. Angle Measurement: We measure the slight change in the star's apparent position against the background of distant stars. This angular shift is called parallax.
3. Trigonometry: Using trigonometry (specifically the tangent function), we can calculate the distance to the star based on the measured parallax angle and the known baseline.
Important Note: Parallax only works for relatively nearby stars. For more distant stars, other techniques like standard candles (e.g., Cepheid variables) or redshift measurements are used.
