Until the 15th century 48 constellations were recognized by astronomers. Most of them were visible from observation points in Greece/Rome. Ptolemy documented the list of constellations.
When Europeans explorers started moving into the southern hemisphere, they started adding the constellations in the southern sky to the list. Between the 15th and the 18th centuries, more constllations were added to the list
There were no clear boundaries between the constellations until the beginning of the 20th century! IAU (International Astronomical Union) published a constellation map with clear boundaries in 1930.
Do you know?
They divided the celestial sphere into twenty seven equal divisions, from the north to the south poles. Mantras list the characteristics of each division through an amazing insight into the structure of our galaxy.
27 equal divisions