At dawn on Easter Sunday, Dante reaches the shores of Purgatory “to see—once more—the stars.” The tall mountain surrounded by the ocean rises in the southern hemisphere, at the antipodes of Jerusalem, and the Poet sees a different sky there from the one familiar to him. His attention is attracted to four stars that Amerigo Vespucci later identified as the constellation now known as the Southern Cross, which marks the celestial South Pole. When Vespucci crossed the Equator along the coast of Brazil in 1499 and, like Dante, lost his northern celestial bearings (“the other pole | from which the Wain had disappeared by now,” Purgatorio I, 30), the Poet’s words guided him in his search for the celestial South Pole.
Then I turned to the right, setting my mind upon the other pole, and saw four stars not seen before except by the first people.
Purgatorio I, 22-24.