Well...since you steadily ignore them I have to hammer them into you.
You ignore his german family, his german mother, his german mother tongue, even that he described himself as german and signed his manuscripts that way.
The only argument going for you (or so you think) is his political allegiance as he supported Poland against the Teutonic Order...but sorry...that doesn't make him polish!
So yes, it seems I have to repeat the facts again and again...
An objective gathering of known facts about this discussion, the best and most comprehensive source so far.
I especially like the conclusion:
One can say summarizing, that Copernicus' working language was Latin, his mother tongue was German, his sovereign was Polish and his father tongue was probably Polish. He is undisputedly a Central-European.
I'm all for sharing him, but I won't stand by idle when Poles claims him solely for themselves!