Although officially enrolled in Bologna in canon law, then in civil law, Copernicus also had a deep interest in astronomy, and he was not unaware that masters from Krakow were regularly called to Bologna to teach this discipline and also to profess astrology
"The 15th century had come to an end when I arrived in Bologna and, in particular, at its infamous University. I enrolled in the register of jurists of the German nation, which included young men from Silesia, Prussia and Pomerania, as well as students from other lands. My stay lasted about three years. Without any false modesty, I could consider myself a multifaceted young man, since I was studying civil law in the city of Ferrara at the same time, but my greatest muse was always astronomy. In fact, it was in that year that I made my first astronomical observations.
In all honesty, my interests were not in canon law but in the humanities and astronomy, and I did not receive my doctorate in canon law until seven years later, by means of a second return to Italy. It was in Bologna that, among the professors, there was one, already very famous at the time, who was to become my mentor and most beloved teacher, Domenico Maria Novara. Later, I developed new ideas inspired by the Epitome in Almagestum Ptolemei by George von Peuerbach and Johannes Regiomontanus. Ergo, I verified his observations on peculiarities of the theory of the motion of the moon, so much so that there I conducted a memorable observation of the occultation of a star called Aldebaran, in the constellation Taurus. This was one of the first immense satisfactions of my life."
It is known that Copernicus found his stay in Bologna particularly expensive in view of his resources as a student, and that he sometimes ran out of money...
By Stefano, author of the tour "Copernicus. The silent revolution"