  We report the results of our follow-up campaign of the supernova impostor PSN
J09132750+7627410, based on optical data covering $\sim250\,\rm{d}$. From the
beginning, the transient shows prominent narrow Balmer lines with P-Cygni
profiles, with a blue-shifted absorption component becoming more prominent with
time. Along the $\sim3\,\rm{months}$ of the spectroscopic monitoring, broad
components are never detected in the hydrogen lines, suggesting that these
features are produced in slowly expanding material. The transient reaches an
absolute magnitude $M_r=-13.60\pm0.19\,\rm{mag}$ at maximum, a typical
luminosity for supernova impostors. Amateur astronomers provided
$\sim4\,\rm{years}$ of archival observations of the host galaxy, NGC 2748. The
detection of the quiescent progenitor star in archival images obtained with the
Hubble Space Telescope suggests it to be an $18-20$\msun white-yellow
supergiant.
