  With an equilibrium temperature above 2500 K, the recently discovered
HAT-P-70 b belongs to a new class of exoplanets known as ultra-hot Jupiters:
extremely irradiated gas giants with day-side temperatures that resemble those
found in stars. These ultra-hot Jupiters are among the most amenable targets
for follow-up atmospheric characterization through transmission spectroscopy.
Here, we present the first analysis of the transmission spectrum of HAT-P-70 b
using high-resolution data from the HARPS-N spectrograph of a single transit
event. We use a cross-correlation analysis and transmission spectroscopy to
look for atomic and molecular species in the planetary atmosphere. We detect
absorption by Ca II, Cr I, Cr II, Fe I, Fe II, H I, Mg I, Na I and V I, and we
find tentative evidence of Ca I and Ti II. Overall, these signals appear
blue-shifted by a few km s$^{-1}$, suggestive of winds flowing at high velocity
from the day-side to the night-side. We individually resolve the Ca II H & K
lines, the Na I doublet, and the H$\alpha$, H$\beta$ and H$\gamma$ Balmer
lines. The cores of the Ca II and H I lines form well above the continuum,
indicating the existence of an extended envelope. We refine the obliquity of
this highly misaligned planet to $107.9^{+2.0}_{-1.7}$ degrees by examining the
Doppler shadow that the planet casts on its A-type host star. These results
place HAT-P-70 b as one of the exoplanets with the highest number of species
detected in its atmosphere.
