dcf21 / precession Goto Github PK

I think the date scale on the planisphere may be mislabeled, perhaps flipped around 2000 CE.
For instance, if the year is set to 2000 BCE, this puts the celestial pole (center of window) in Cepheus, whereas according to the chart on the website, the NCP is in Cepheus in 6000CE.

It might be interesting to increase the precision of the path of the pole.

The task of computing precession over long time scales with precision was described in this 2011 paper. It would be interesting to make the comparison between the approximate and precise algorithms, even if it's only to quantify the limitations of the approximate algorithm.

I think the date scale on the planisphere may be mislabeled, perhaps flipped around 2000 CE.
For instance, if the year is set to 2000 BCE, this puts the celestial pole (center of window) in Cepheus, whereas according to the chart on the website, the NCP is in Cepheus in 6000CE.