The star-forming region in Orion KL.

We have studied the fine structure of the active H2O supermaser emission region in Orion KL with an angular resoln. of 0.1 mas. We found central features suggestive of a bipolar outflow, bullets, and an envelope which correspond to the earliest stage of low-mass star formation. The ejector is a bright compact source ?0.05 AU in size with a brightness temp. Tb ~ 1017 K. The highly collimated bipolar outflow ~30 has a velocity vej ~ 10 km s-1, a rotation period of ~0.5 yr, a precession period of ~10 yr, and a precession angle of ~33 Deg. Precession gives rise to a jet in the shape of a conical helix. The envelope amplifies the radio emission from the components by ~3 orders of magnitude at a velocity v = 7.65 km s-1. [on SciFinder (R)]