0 Assigned ID: 289 ----- Attempting Submission 1 (Thu Apr 09 22:17:12 GMT 2015) ----- HST Phase I Proposal 289 (snarch-cycle23-v4_apt.pdf.apt) successfully submitted. Receipt: # 289-1 ----- Attempting Submission 2 (Thu Apr 09 22:19:39 GMT 2015) ----- HST Phase I Proposal 289 (snarch-cycle23-v4_apt.pdf.apt) successfully submitted. Receipt: # 289-2 ----- Attempting Submission 3 (Fri Apr 10 17:38:12 GMT 2015) ----- The locations of supernovae (SNe) in the local stellar and gaseous environment in galaxies, as measured in high-resolution WFPC2, NICMOS, ACS, and WFC3 images, contain important clues to their progenitor stars. They provide accurate determinations of any association of SNe with HII regions or star clusters. Since multi-filter observations are generally available, we can assess the local stellar population, setting constraints on the mass of the progenitor; we can also search for possible attenuation of the SN by dust in the host galaxy by studying the colors of the stars in its environment. By checking the fields for background sources, we can correct the existing SN light curves and luminosities if necessary. When a SN has been observed incidentally, information can be gained on its optical and UV emission. Deep HST images can be used to find light echoes of SNe, as well as recover SNe interacting with circumstellar material at very late times. A direct search for the progenitor stars of SNe can be made in pre-existing HST images of their locations; as the number of archival HST images steadily increases, along with the number of newly discovered SNe, positive identifications become progressively more likely. In Cycle 23, we plan to extend our successful work from previous cycles. This proposal is complementary to our Cycle 23 snapshot proposal, whose primary purpose is to obtain late-time photometry of SNe. It is also complementary to our Cycle 23 ToO proposal, which is largely designed to pinpoint the locations of new SNe to help determine their progenitor stars. RESOLVED STELLAR POPULATIONS 0 Regular false false false false false SUPPORTED