The Star Formation Histories of Disk and E/S0 Galaxies from Resolved
  Stars
  The resolved stellar populations of local galaxies, from which it is possible
to derive complete star formation and chemical enrichment histories, provide an
important way to study galaxy formation and evolution that is complementary to
lookback time studies. We propose to use photometry of resolved stars to
measure the star formation histories in a statistical sample of galaxy disks
and E/S0 galaxies near their effective radii. These measurements would yield
strong evidence to support critical questions regarding the formation of
galactic disks and spheroids. The main technological limitation is spatial
resolution for photometry in heavily crowded fields, for which we need
improvement by a factor of ~10 over what is possible today with filled aperture
telescopes.
