What are the stars and constellations seen at different latitudes related to?

The stars that can be observed at different latitudes are different. Because the earth is round, the observer must have a ground plane in the same position to block his line of sight, thus forming a visual blind spot. Only certain starry sky can be seen at different latitudes, so the number of stars must be different.

Obviously, the Southern Constellation was gradually determined after the successful voyage around the world in the 17th century, and then it was observed by navigators, so there were many advanced scientific instruments to name the Southern Constellation. Such as telescope base, compass base, microscope base, compass base, etc.

As long as the latitude is the same and the longitude is different, but the time for observing stars in the morning and evening is different, the number of observed stars should be the same.