  Ultra-hot Jupiters are defined as giant planets with equilibrium temperatures
larger than 2000 K. Most of them are found orbiting bright A-F type stars,
making them extremely suitable objects to study their atmospheres using
high-resolution spectroscopy. Recent studies show a variety of atoms and
molecules detected in the atmospheres of this type of planets. Here we present
our analysis of the newly discovered ultra-hot Jupiter TOI-1431b/MASCARA-5b,
using two transit observations with the HARPS-N spectrograph and one transit
observation with the EXPRES spectrograph. Analysis of the Rossiter-McLaughlin
effect shows that the planet is in a polar orbit, with a projected obliquity $
\lambda = -155^{+20}_{-10}$ degrees. Combining the nights and applying both
cross-correlation methods and transmission spectroscopy, we find no evidences
of CaI, FeI, FeII, MgI, NaI, VI, TiO, VO or H$\alpha$ in the atmosphere of the
planet. Our most likely explanation for the lack of atmospheric features is the
large surface gravity of the planet.
