Hi all, sort of an unconventional question here. I hope it doesn't violate the forum rules, but if it does, do let me know and I'll retract it!

Can anyone who is well-versed in astrometry or the history of astronomy provide any sources (with mathematical workings) on how Friedrich Bessel managed to triangulate the position of 61 Cygni via the parallax angle of 0.314"? I've tried working it out myself, but cannot figure out the angle of deviation of 61 Cygni from the ecliptic given Earth's tilt and the star's Ra and declination.

Alternatively, likewise sources for how Thomas Henderson figured out that of Alpha Centauri or Friedrich Struve for Vega would work too. Or if any kind and mathematically inclined souls are able to help me on this, I would greatly appreciate it!