UV and optical obs. of type Ic SN 2020oi

We undertake a comprehensive analysis to characterize the evolution of SN 2020oi and constrain its progenitor system. We detect flux in excess of the fireball rise model {delta}t~2.5d from the date of explosion in multiband optical and UV photometry from the Las Cumbres Observatory and the Neil Gehrels Swift Observatory, respectively.

The derived SN bolometric luminosity is consistent with an explosion with M_ej_=0.81+/-0.03M_{sun}_, E_k_=0.79+/_0.09x10^51^erg/s, and M_Ni56_=0.08+/-0.02M_{sun}_. Inspection of the event's decline reveals the highest {Delta}m_15,bol_ reported for a stripped-envelope event to date. Modeling of optical spectra near event peak indicates a partially mixed ejecta comparable in composition to the ejecta observed in SN1994I, while the earliest spectrum shows signatures of a possible interaction with material of a distinct composition surrounding the SN progenitor.