We describe the optical spectropolarimetric monitoring program at Steward Observatory centered around gamma-ray-bright blazars and the LAT Monitored Source List planned for Fermi Cycles 2–4 .
The large number of measurements made during Cycle 1 of the Fermi mission are available to the research community and the data products are summarized ( see http : //james.as.arizona.edu/ \sim psmith/Fermi ) .
The optical data include spectropolarimetry at a resolution of \sim 20 Å , broad-band polarization and flux measurements , and flux-calibrated spectra spanning 4000-7600 Å .
These data provide a comprehensive view of the optical variability of an important sample of objects during the Fermi Era .
In addition to broad-band flux and linear polarization monitoring , the spectra allow for the tracking of changes to the spectral index of the synchrotron continuum , importance of non-synchrotron emission features , and how and when the polarization varies with wavelength , an important clue as to the structure of the emission region or the identification of multiple nonthermal components .
As an illustration , we present observations of 3C 454.3 obtained in 2009 September during an exceptionally bright gamma-ray flare .
The blazar was optically bright during the flare , but except for a few short periods , it showed surprisingly low polarization ( P < 5 % ) .
Opportunities exist within the Fermi research community to coordinate with our long-term optical monitoring program toward the goal of maximum scientific value to both the Fermi and associated radio VLBI monitoring of blazars .