Evaluation of the Underlying Event in pp collisions at $\sqrt{s} =$ 200 GeV at STAR

The interpretation of STAR's published inclusive jet cross-section and longitudinal asymmetry data relies on a robust connection between the experimentally measured and theoretically calculated jet energy scale (JES). Evaluation of the underlying event (UE), the isotropic distribution of particles resulting from partonic interactions not associated with the inelastic collision producing the jet, is a necessary step in the quantification of the JES in hadronic collisions. This presentation will discuss progress toward the extraction of the UE in $\sqrt{s}=$ 200 GeV proton collisions produced at the Relativistic Heavy Ion Collider (RHIC) and detected in the Solenoidal Tracker at RHIC (STAR). Techniques, developed by the CDF collaboration at Fermilab, are used to isolate and charactertize the UE in dijet events. Comparisons between CDF and STAR results will be evaluated and progress towards quantifying the UE contribution to the JES for jets reconstructed at STAR will be reported.