Four-year observations of T Tauri with adaptive optics

We report here on a series of adaptive optics observations of T Tauri made from Dec. 1993 to Nov. 1997. Observations show an arc-like structure extending toward north and north-west. On the south side a bright tail-like structure extends radially in the south-west direction. Both structures seem to be produced by dust scattering. Close to T Tauri, the south structure forms bright clumps near a radio source called T Tau R. From one year to another, the clumps appear to be moving toward T Tauri. The infrared companion is detected for the first time in the J band. Its brightness peaked again in 1996, although the maximum was less pronounced than in 1990. It is found to be resolved with a radius of 54 milliarcsec (7.6 AU at 140 pc). Surprisingly, its orbital speed is found to exceed the escape velocity. This leads to the conjecture that T Tauri is the result of a collision between a young star and a protostar, possibly explaining the peculiar molecular hydrogen emission found in this object. The protostar envelope would have been torn apart forming Burnham’s nebula and leaving the protostar naked, that is visible in the near IR .