Episode 1 of 2
Bessel Measures 61 Cygni Parallax
- When
- 1837–1838
- Where
- Königsberg Observatory
Friedrich Bessel conducted an observational campaign in 1837–1838 at Königsberg Observatory, measuring the parallax of 61 Cygni using a Fraunhofer heliometer.
Bessel, a friend of Struve, carried out an intense observational campaign in 1837–1838 at Königsberg Observatory for the star 61 Cygni using a heliometer. He published his results in 1838, determining a parallax of 0.314 arcseconds, which indicated the star was 10.3 light-years away. This was the first reliable distance estimate for any star other than the Sun.
Sources
- Stellar parallax Wikipedia, revision of 2026-07-09
- Friedrich Wilhelm Bessel Wikipedia, revision of 2026-08-29
- 61 Cygni Wikipedia, revision of 2026-09-30
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