16500

Supernova (SN) 2019ehk in M100 is the closest known Calcium-rich (Ca-rich) transient and the only object in this class with an X-ray detection. Prompt comma high-cadence follow-up of this transient across the EM spectrum comma in addition to pre-explosion HST imaging comma has indicated that the progenitor star was likely low mass (e.g. comma white dwarf or <10Msun) and surrounded by dense circumstellar material (CSM) whose geometry-density was capable of producing luminous X-ray emission as well as a double-peaked optical light curve. The close proximity of SN 2019ehk provided the first opportunity to obtain multi-color HST observations out to 400 days post explosion comma which revealed a pure radioactive decay power source. Ca-rich transients typically decrease in magnitude rapidly and therefore comma prior to SN 2019ehk comma their late-time decline rate and power source at t<400 days was V1.0. Here we propose multi-color imaging of SN 2019ehk in order to search for emission from a bound remnant white dwarf as predicted by a favored progenitor model for this explosion. Detection and characterization of such a remnant will provide a novel constraint on the progenitors of Ca-rich transients and provide a new window into the explosion itself. Additionally comma these observations will provide the best constraints to date on a potential non-degenerate companion star in any thermonuclear SN progenitor system such as Ca-rich SNe.