SED evolution of young stellar objects in Taurus studied with Spitzer-IRS
          Elise Furlan, Cornell U.
          Dan M. Watson, U. of Rochester
          William J. Forrest, U. of Rochester
          Keven I. Uchida, Cornell U.
          Nuria Calvet, CfA
          Paola D'Alessio, UNAM
          Lee Hartmann, CfA
          Joel D. Green, U. of Rochester
          Ben Sargent, U. of Rochester
          Luke D. Keller, Ithaca College
          Greg C. Sloan, Cornell U.
          Terry L. Herter, Cornell U.
          Joan Najita, NOAO

          We present Spitzer-IRS spectra of young stellar objects in Taurus, whose spectral energy distribution (SED) displays an infrared excess, indicative of the presence of circumstellar material. We analyzed the SED properties of these YSOs and compared them with a grid of models. We used the inferred physical structure of the circumstellar environment and the properties of the dust within to order the YSOs of this study into an evolutionary sequence. By correlating parameters which characterize the circumstellar environment with the spectral shape in the mid-infrared, we derived mid-IR diagnostics for SED evolution.