SN 2019hcc: a Type II supernova displaying early O <scp>ii</scp> lines

ABSTRACT We present optical spectroscopy together with ultraviolet, optical, and near-infrared photometry of SN 2019hcc, which resides in a host galaxy at redshift 0.044, displaying sub-solar metallicity. The supernova spectrum near peak epoch shows ‘w’ shape around 4000 Å is usually associated O ii lines typical Type I superluminous supernovae. 2019hcc post-peak spectra show well-developed H ? P-Cygni profile from 19 d past maximum its light curve, terms absolute luminosity evolution, resembles that fast-declining Hydrogen-rich (SN IIL). object does not any unambiguous sign interaction as there no evidence narrow the or undulations curve. Our tardis spectral modelling first carbon, nitrogen, oxygen (CNO) 000 K reproduce suggests combination non-thermally excited CNO metal 8000 could feature seen Å. Bolometric light-curve reveals be fit magnetar model, showing relatively strong magnetic field (B &amp;gt; 3 × 1014 G), matches rise time without powering up curve to luminosities. high-energy photons produced by would then responsible for detected lines. As consequence, Å, attributed ii, only shown supernovae hence it should treated sole belonging such type.