Assigned ID: 975 ----- Attempting Submission 1 (Sat Feb 25 00:16:19 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 2 (Sat Feb 25 00:40:06 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 3 (Sat Feb 25 00:51:07 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 4 (Sat Feb 25 00:54:42 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 5 (Sat Feb 25 00:56:05 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 6 (Sat Feb 25 00:56:57 GMT 2012) ----- HST Phase I Proposal 975 (iibarchive.apt) successfully submitted. ----- Attempting Submission 7 (Sat Feb 25 00:59:10 GMT 2012) ----- Core-collapse supernovae (SN) signal the deaths of massive stars, and their spectra, used to classify SN into types, reveal the state of the progenitor's outer envelope before the explosion. Using SDSS photometry, we have recently found strong, type-dependent patterns in the host galaxy's color and surface brightness near explosion sites. Exceptionally blue environments are typical of Type IIb SN, whose progenitors retain only a thin outer hydrogen shell. SN Ic, whose spectra are consistent with more complete loss of the progenitor's outer hydrogen and helium envelopes, explode in host regions with high u'-band surface brightness. We propose photometry of the resolved stellar populations near the sites of 35 stripped-envelope SN within ~25 Mpc. We will infer the age and mass distributions of the nearby young stellar population from isochrone modeling of the color magnitude diagram. The proposed analysis will reveal how pre-explosion mass loss depends on progenitor mass as well as the natal host environment. HOT STARS 12 Medium false 0.0 0.0 false false false false SUPPORTED