Tycho Brahe was another famous astronomer who lived from 1546 to 1601. He created the tychonic model. The tychonic model stated that the Sun revolved around the Earth but all other planets revolved around the Sun
Tycho also observed that Saturn and Jupiter were unusually close to each other and eventually passed each other. He found out that the existing almanacs and ephemerides were innacurate
Another thing Tycho discovered was "Tycho's star". It was a supernova he called "De Nova Stella".