0 Your proposal could not be saved. Submission aborted. Assigned ID: 969 ----- Attempting Submission 1 (Fri Mar 06 23:59:56 GMT 2020) ----- HST Phase I Proposal 969 successfully submitted. Receipt: # 969-1 ----- Attempting Submission 2 (Sat Mar 07 00:01:46 GMT 2020) ----- HST Phase I Proposal 969 successfully submitted. Receipt: # 969-2 ----- Attempting Submission 3 (Sat Mar 07 00:47:32 GMT 2020) ----- The mechanisms driving removal of envelopes of stripped-envelope supernova (SE SN) progenitors is a key challenge to our understanding of massive star evolution. Type IIb SNe (SNe IIb) are particularly valuable for addressing this challenge because of the availability of direct progenitor/companion identifications in several cases. HST archives are the primary source of these fortitutous pre-SN images and provide the strongest constraints for theoretical models. Unfortunately, current methods for using HST photometry to constrain progenitor properties and understanding their evolutionary mechanisms do not account for the statistical significance of either the observational data or model progenitors. This severely limits both the diagnostic and predictive capabilities of theoretical models. Moreover, differences in assumptions for data reduction by different groups causes variation in inferred progenitor properties for the same data. We propose to conduct a homogenous analysis of archival HST images of all SN IIb with detected progenitors and derive statistical constraints for their progenitor and companion properties. Our analysis will also provide predictions for progenitor and companion properties in HST filters to aid in companion searches. We will release to the community all codes required to reproduce our analysis for any future SN IIb on the successful completion of our project. Such a tool will significantly aid and simplify efforts for understanding SNe IIb progenitors. Given HST's degrading UV sensitivity, such a tool is not only time-critical but also essential in order to make optimal use of HST's unique UV capabilities. Dr. Niharika Sravan is a postdoctoral research associate at Purdue University. She has significant expertise in modeling the evolution of stripped-envelope supernova progenitors, especially with MESA. She is also trained as a data scientist with expertise in applications of statistical methods and machine learning in Astronomy. Prof. Dan Milisavljevic is an expert in multiwavelength observations and interpretations of supernovae, exotic supernovae, other exotic transients, and their progenitors. He also has significant experience analyzing HST images especially those with crowded fields and faint sources. John Banovetz is a graduate student at Purdue University working with Prof. Milisavjevic. He has substantial experience analyzing and reducing HST images. Prof. Vicky Kalogera is an expert in stellar evolution (especially binaries) and population synthesis with applications to LIGO, X-ray binaries, and supernovae. Stellar Physics and Stellar Types 0 Regular false false false true false SUPPORTED