Mid‐infrared Spectroscopy of Disks around Classical T Tauri Stars

We present the first Spitzer Infrared Spectrograph 11 observations of the disks around classical T Tauri stars: spectra in the 5.2-30 µm range of six stars. The spectra are dominated by emission features from amorphous silicate dust, and a continuous component from 5 to 8 µm that in most cases comprises an excess above the photosphere throughout our spectral range. There is considerable variation in the silicate feature/continuum ratio, which implies variations of inclination, disk flaring, and stellar mass accretion rate. In most of our stars, 1