There is obvious fact: axis of Earth rotation must not be pointed at the area of North Star during one year cycle. But it is pointed. Thus, the official Science either lies or is incompetent. Correct? Yes. And the Flat Earth model is consistent with Nature here.
The classical reasoning (in words), is presented in the publication (click on the public link) below. Steps to write math to it: 1. using the Newton Gravity to show, that ship's hull, which moves along the orbit has weightlessness. It is obviously true. Thus, from definition of inertial system we conclude, that ship is such system. 2. To recall the Law in Nature: the angular momentum does conserve in inertial system. 3. To make conclusion: rotating body does conserve the angle to its orbit.
https://www.researchgate.net/publication/324950713_Can_someone_show_in_detail_the_derivation_of_Celestial_Pole_precession_within_General_Relativity_formalismThis might be more up to date:
http://vixra.org/abs/1805.0048