2026/07/28 by Monalisa Dubey, Kuntal Misra, Naveen Dukiya +16
#astro-ph.HE
We present optical photometric and spectroscopic observations of the Type~II supernova SN~2022xus. The SN reached its peak \em V band magnitude of -16.32 mag within ∼7 days of explosion, followed by a plateau phase lasting ∼94 days with a declination rate of ∼1.2 mag (100 day)-1. Early time spectra exhibit broad features that could be caused by the blending of several high-ionisation lines, likely arising from a relatively weak interaction between the SN ejecta and the surrounding circumstellar medium (CSM). Compared to typical Type~IIP SNe, SN~2022xus exhibits a smaller Hα absorption-to-emission ratio (a/e), indicating a relatively small hydrogen envelope mass at the time of explosion. From nebular-phase spectroscopy and bolometric light curve modelling, the progenitor mass is estimated to be in the range of 12 -- 15 M_\odot. The multi-band light curve modelling using REDBACK infers a similar progenitor mass, a low mass-loss rate, and a confined CSM. Although several photometric and spectroscopic characteristics place the SN within the Type~IIL population, it displays mixed properties of both Type~IIP and Type~IIL SNe and cannot be cleanly classified into either subclass. We therefore identify SN~2022xus as a transitional event between Type~IIP and Type~IIL SNe, providing further evidence for a continuum between these two classes.