Measuring the distances to stars using trigonometric parallax . A method that dates back to 18th century . Many surveyors also use this kind of measurement to draw accurate maps of the surface of Earth.
Then in 1838 Friedrich Bessel made the first successful parallax measurement ever, for the star 61 Cygni. Once a star’s parallax is known, its distance from Earth can be computed trigonometrically. The following video demonstrates the parallax method of measurement.