This document summarizes observations of the giant exoplanet τ Boötis b using high-resolution spectroscopy to detect carbon monoxide absorption in the planet's atmosphere. Key findings include: 1) The observations trace the planet's radial velocity over its orbit, determining an orbital inclination of 44.5±1.5 degrees and true planet mass of 5.95±0.28 Jupiter masses. 2) Carbon monoxide absorption indicates the planet's atmosphere has a temperature decreasing with altitude rather than a thermal inversion, contrasting with other highly irradiated planets. 3) This supports models where strong UV radiation from the active host star destroys compounds causing thermal inversions in other planets' atmospheres.