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Keywords from Image Description:
Poli celesti.svg Sfera celeste sono evidenziati poli celesti poli dell'orizzone il polo celeste elevato P' il polo celeste depresso lo Zenith Z' il Nadir il centro della Terra della sfera celeste l'osservatore sulla superficie terrestre Celestial sphere with poles is the center of the celestial sphere is the observer Own CAV Calotte