  Over the last decade, studies of large samples of binary systems identified
chemical anomalies, and showed that they might be attributed to planet
formation or planet engulfment. However, both scenarios have primarily been
tested in pairs without known exoplanets. In this work, we explore these
scenarios in the newly detected planet-hosting wide binary TOI-1173 A/B
(projected separation $\sim 11,400$ AU) using high-resolution MAROON-X and
ARCES spectra. We determined photospheric stellar parameters both by fitting
stellar models and via the spectroscopic equilibrium approach. Both analyses
agree and suggest that they are cool main sequence stars located in the thin
disc. A line-by-line differential analysis between the components (B$-$A)
displays an abundance pattern in the condensation temperature plane where the
planet-hosting star TOI-1173 A is enhanced in refractory elements such as iron
by more than 0.05 dex. This suggests the engulfment of $\sim$18 M$_{\oplus}$ of
rocky material in star A. Our hypothesis is supported by the dynamics of the
system detailed in our companion paper Yana Galarza et al. 2024, which suggest
that the Super-Neptune TOI-1173 A $b$ might have been delivered to its current
short period ($\sim7$ days) through circulatization and von Zeipel-Lidov-Kozai
mechanisms, thereby triggering the engulfment of inner rocky exoplanets.
