CORONOGRAPHIC IMAGING OF T-TAURI - DISCOVERY OF AN OPTICAL JET IN BURNHAM NEBULA

We present coronographic images of T Tauri and its surrounding nebula (Burnham nebula) obtained with the STScI coronograph at Calar Alto (Sp ain) and with the STScI-Torino coronograph at ESO-NTT in H alpha 6563, [SII] 6716-6731 and 6670/80 Angstrom satellite continuum filters. Tak ing advantage of the subarcsec seeing conditions, we mapped the circum stellar environment down to 2'' from the star, corresponding to 320 A. U. at the T Tauri distance of 160 pc. Both the H alpha and [SII] image s reveal a complex morphology, characterized by several clumps of shoc k-excited gas superimposed on large scale continuum emission. In parti cular, we detected a jet-like feature departing from the immediate sur roundings of the star in a southly direction that leads to a region of shock excited clumps. A curved filament departs from this region, cro ssing Burnham nebula up to the previously known Herbig-Haro object HH A (Schwartz 1990). The south-western part of Burnham nebula is charact erized by a number of small, nearly circular clumps. A faint, isolated HH object is also present in the northern part of the nebula. Taking into account all the available data, we suggest that the optical jet i s emitted by TTau S roughly along the plane of the sky. The jet at fir st moves into the neutral components originating the shock excited kno ts and then impacts with the edges of the cavity associated to the out flows. The jet wiggling due to the orbital motion of the emitting sour ce and/or to precession phenomena could explain the peculiar excitatio n status of the Burnham nebula.