The state of the question as received by Copernicus is summarized in the "Theoricae novae planetarum" by Georg von Peuerbach, compiled from lecture notes by Peuerbach's student Regiomontanus in 1454, but not printed until 1472. Peuerbach attempts to give a new, mathematically more elegant presentation of Ptolemy's system, but he does not arrive at heliocentrism. Regiomontanus was the teacher of Domenico Maria Novara da Ferrara, who was in turn the teacher of Copernicus. There is a possibility that Regiomontanus already arrived at a theory of heliocentrism before his death in 1476, as he paid particular attention to the heliocentric theory of Aristarchus in a late work, and mentions the "motion of the Earth" in a letter.