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We study the resolved stellar populations and derive the star formationhistory of NGC 5474, a peculiar star-forming dwarf galaxy at a distance of$\sim 7$ Mpc, using Hubble Space Telescope Advanced Camera for Surveys datafrom the Legacy Extragalactic UV Survey (LEGUS) program. We apply an improvedcolour-magnitude diagram fitting technique based on the code SFERA and use thelatest PARSEC-COLIBRI stellar models. Our results are the following. Theoff-centre bulge-like structure, suggested to constitute the bulge of thegalaxy, is dominated by star formation (SF) activity initiated $14$ Gyr ago andlasted at least up to $1$ Gyr ago. Nevertheless, this component shows clearevidence of prolonged SF activity (lasting until $\sim 10$ Myr ago). Weestimate the total stellar mass of the bulge-like structure to be $(5.0 \pm0.3) \times 10^{8}$ \MSUN. Such a mass is consistent with published suggestionsthat this structure is in fact an independent system orbiting around and notwithin NGC 5474's disc. The stellar over-density located to the South-West ofthe bulge-like structure shows a significant SF event older than $1$ Gyr, whileit is characterised by two recent peaks of SF, around $\sim10$ and $\sim100$Myr ago. In the last Gyr, the behavior of the stellar disc is consistent withwhat is known in the literature as `gasping'. The synchronised burst at $10-35$Myr in all components might hint to the recent gravitational interactionbetween the stellar bulge-like structure and the disc of NGC 5474.

The spatially resolved star formation history of the dwarf spiral galaxy NGC 5474