Code review comment for lp:~georg-zotti/stellarium/gz_fix-ecliptic-obliquity

> Oh! One important note - pole precision line is not a circle, it's spirale.
> Current implementation can confuse many peoples. I think this line may be
> implemented as line with some range of the dates, like orbits in Satellites
> plugin.

Yes it's a spiral. But what I show here is the "instantaneous circle" which at least visualizes the concept. Avid observers will note that stars orbiting the instantaneous pole of ecliptic of date next to this circle will intersect the circle, and that Polaris will have a different polar distance next time it is pole star. I think this is perfectly enough as visualisation for now.

When the feature request "orbit with labeled date marks" has been implemented, maybe someone can also implement the spiral with date labels then?

In these time ranges (tens of thousands of years) it's sad to see that VSOP87 only covers less than 1/2 cycle... But I have never seen the answer to "what happens outside -4000...+8000" as clearly.

DE431 should show a bit more than 1 cycle, at least.