First Measurement Of The Distance To A Star

Friedrich Wilhelm Bessel was the first person to measure the distance to a star other than the Sun. He calculated the parallax angle of 61 Cygni with respect to two points on the Earth's orbit in 1838. His measured value was 1.52 μrad. This implied a distance of 60.5 trillion miles! His result was later discovered to have an error of less than 10%.