The first great optical observer. His primary contributions to astrophysics were the design and development of observing instruments and the precise data he collected on the motions of the celestial bodies in the pre-telescope era. His data were accurate to within roughly 1 to 2 arc minutes. Before his time, the accuracy was on the order of 15 arc minutes. (Comment--A simple thing which Tycho did which greatly improved his accuracy was to make several measurments of quantities and to then average his results in order to arrive at his final answer. This is standard practice today, but was highly unusual during Tycho's time.) Further, in contrast to earlier observers, Tycho observed objects throughout their cycles rather only at particular times, such as opposition and quadrature.
The data were complete and accurate enough to allow
people to rule out theories of the motions of the celestial bodies. The
result of his (and other people's) studies was to show that neither the
Ptolemaic nor the Copernican models were acceptable. Both models were
not consistent with the data!!!
This was the first step toward the development of an understanding of the Solar System.
Oh, and like all observers, he also proposed his own geo-centric model for planetary motion.
Other Accomplishments
