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, high-cadence follow-up of this transient across the EM spectrum, in addition to pre-explosion HST imaging, has indicated that the progenitor star was likely low mass and surrounded by dense circumstellar material (CSM) whose geometry/density was capable of producing luminous X-ray emission as well as a double-peaked light curve. The close proximity of SN 2019ehk provides the first opportunity to track the photometric evolution of a Ca-rich transient at late phases (>300 days) when the SN luminosity is governed by radioactive decay and/or additional power sources e.g., CSM, and is too faint for ground-based observatories. These objects typically decrease in magnitude rapidly and thus their late-time decline rate and power source is unknown. Here we propose multi-color imaging of SN 2019ehk in order to understand its late-time bolometric behavior and to constrain the total mass of Ni-56 synthesized in the explosion. This will allow us to test whether SN 2019ehk is powered solely by radioactive decay or by additional CSM at large distances from the progenitor system.
|Effective start/end date||6/1/20 → 5/31/23|
- Space Telescope Science Institute (HST-GO-16075.004-A//NAS5-26555)
- National Aeronautics and Space Administration (HST-GO-16075.004-A//NAS5-26555)