Hubble Space Telescope WFPC2 Imaging of SN 1979C and Its Environment
  The locations of supernovae in the local stellar and gaseous environment in galaxies contain important clues to their progenitor stars. As part of a program to study the environments of supernovae using Hubble Space Telescope (HST) imaging data, we have examined the environment of the Type II-L SN 1979C in NGC 4321 (M100). We place more rigorous constraints on the mass of the SN progenitor, which may have had a mass M \approx 17--18 M_sun. Moreover, we have recovered and measured the brightness of SN 1979C, m=23.37 in F439W (~B; m_B(max) = 11.6), 17 years after explosion. . 
Schuyler D. Van Dyk, Chien Y. Peng, Aaron J. Barth, Alexei V.   Filippenko, Roger A. Chevalier, Robert A. Fesen, Claes Frans...