10-MU-M IMAGES AND SPECTRA OF T-TAURI STARS

T Tauri stars are young stars usually surrounded by dusty disks simila r to the one from which we believe our own Solar System formed. Most T Tauri stars exhibit a broad emission or absorption band between 7.5 a nd 13.5 mum which is attributed to silicate grains in the circumstella r environment. We imaged three spatially resolved T Tauri binaries thr ough a set of broadband filters which include the spectral region occu pied by the silicate band. Two of these objects (T Tauri and Haro 6-10 ) are ''infrared companion'' systems in which one component is optical ly much fainter but contributes strongly in the infrared. Both infrare d companions exhibit a deep silicate absorption which is not present i n their primaries, indicating that they suffer very strong local extin ction which may be due to an edge-on circumstellar disk or to a dense shell. We also took low resolution spectra of the silicate feature of two unresolved T Tauris to look for narrow features in the silicate ba nd which would indicate the presence of specific minerals such as oliv ine. We observed GK Tau, for which Cohen and Witteborn (1985) reported a narrow emission feature at 9.7 mum, but do not find evidence for th is feature, and conclude that it is either time-dependent or an artifa ct of absorption by telluric ozone.