Infrared interferometric observations of young stellar objects

We present infrared observations of four young stellar objects made using the Palomar Testbed Interferometer (PTI). For three of the sources, T Tau, MWC 147, and SU Aur, the 2.2 mum emission is resolved at the Pn's nominal fringe spacing of 4 mas, while the emission region of AB Aur is overresolved on this scale. We fit the observations with simple circumstellar material distributions and compare our data to the predictions of accretion disk models inferred from spectral energy distributions. We find that the infrared emission region is tenths of an AU in size for T Tau and SU Aur and similar to1 AU for MWC 147.