  With high equilibrium temperatures and tidally locked rotation, ultra-hot
Jupiters (UHJs) are unique laboratories within which to probe extreme
atmospheric physics and chemistry. In this paper, we present high-resolution
dayside spectroscopy of the UHJ WASP-189b obtained with the new Gemini
High-resolution Optical SpecTrograph (GHOST) at the Gemini South Observatory.
The observations, which cover three hours of post-eclipse orbital phases, were
obtained during the instrument's System Verification run. We detect the
planet's atmosphere via the Doppler cross-correlation technique, and recover a
detection of neutral iron in the planet's dayside atmosphere at a significance
of 7.5$\sigma$ in the red-arm of the data, verifying the presence of a thermal
inversion. We also investigate the presence of other species in the atmosphere
and discuss the implications of model injection/recovery tests. These results
represent the first atmospheric characterization of an exoplanet with GHOST's
high-resolution mode, and demonstrate the potential of this new instrument in
detecting and studying ultra-hot exoplanet atmospheres.
