What was Nicolaus Copernicus's connection to Tycho Brahe?

Answer 1

Since Tycho was born three years after Copernicus died, not much. Tycho didn't accept Copernicus's heliocentric system and tried to introduce a hybrid system in which the other planets rotate around the Sun, but the Sun and its planets and the stars rotate around Earth.

Tycho and Kepler were connected, though. Kepler went to work for Tycho to get access to Tycho's planetary position measurements, the most accurate available at the time. Tycho eventually let Kepler have his Mars data, which enabled Kepler to figure out the laws of planetary motion.