SN 2017jfs optical and NIR light curves

At peak, the object reaches an absolute magnitude of Mg=-15.46+/-0.15mag and a bolometric luminosity of 5.5x10^41^erg/s. Its light curve has the double-peak shape typical of luminous red novae (LRNe), with a narrow first peak bright in the blue bands, while the second peak is longer-lasting and more luminous in the red and near-infrared (NIR) bands.

During the first peak, the spectrum shows a blue continuum with narrow emission lines of H and FeII. During the second peak, the spectrum becomes cooler, resembling that of a K-type star, and the emission lines are replaced by a forest of narrow lines in absorption. About 5 months later, while the optical light curves are characterized by a fast linear decline, the NIR ones show a moderate rebrightening, observed until the transient disappears in solar conjunction.