Using the full power of the HST Archive to Address the Red Supergiant Problem

This program proposes to analyze 376 HST imaging data sets for 68 supernova progenitor stars along with ancillary data necessary for image alignment, photometry, and analysis of the spectral energy distributions of the supernova progenitors. Our goal is to obtain constraints or limiting magnitudes on the pre-explosion photometry of all 68 progenitor stars as well as stars in the immediate environments of the supernova progenitors for isochrone analysis, requiring precise image alignment, photometry, and (where available) template subtraction using late-time HST imaging after the progenitor star has exploded and subsequent supernova has faded. Upon measuring the spectral energy distributions of pre-explosion counterparts and nearby stars, we will pursue the following primary science goals: 1. Use a forward modeling approach to characterize the intrinsic spectral shape of Type II supernova progenitor stars, including parameters for infrared emission due to dust as in Kilpatrick & Foley (2018), MNRAS, 481, 2536 2. Statistically investigate the luminosity and initial mass distribution of Type II supernova progenitor stars, especially the rate at which stars of specific initial masses are predicted to explode as supernovae (and included as sources in our sample) versus implode and thus underrepresented in our sample. We will adopt a statistical approach similar to previous studies in the literature, but with the end goal of modeling various ``final mass distribution'' predictions for successful Type II supernova explosions, such as from Sukhbold et al. (2016), ApJ, 821:38 3. Compare the distribution of Type II supernova peak luminosity, ejecta mass, and nickel mass to the properties of their progenitor stars. 4. Produce a photometric catalog summarizing our findings for supernova progenitor stars and stars in their immediate vicinity for isochrone analysis.