Which of the following astronomers actually met in person?
Nicolaus Copernicus (1473-1543)
Tycho Brahe (1546-1601)
Giordano Bruno (1548-1600)
Galileo Galilei (1564-1642)
Johannes Kepler (1571-1630)
Copernicus couldn't meet with any of the remaining ones, because he died in 1543. From the remaining four any two could meet. It is well known that Brahe met Kepler in Bohemia.
Both Bruno and Brahe have been to Wittenberg and Prague, but I don't think they met there.