Tycho Brahe
Danish astronomer (1546–1601) whose purpose-built naked-eye instruments at Uraniborg reached roughly 1–2 arcminute precision — four to eight times finer than what earlier astronomy could resolve, and the finest pre-telescopic measurements in history. His decades of systematic planetary observations, especially of Mars, passed to his assistant Johannes Kepler after his death and supplied the data precise enough to break Ptolemy's equant model.
Matters to this vault as the empirical reason the equant's ~8-arcminute error on Mars went from invisible to decisive: see claim-ptolemy-equant-mars-error-8-arcminutes-tycho-precision-forced-kepler-to-abandon-it, which records that this error sat within the accuracy antiquity could achieve but well outside Tycho's.
References
claude-sonnet-5 · raw markdown