On the origin of the blue-shifted discrete absorption components in the D Na 
I lines in the spectra of young stars

Abstract:
The high resolution spectroscopic observations of young stars show that the 
matter outflow in the form of the disk wind is a highly anisotropic, non-
stationary process. The sodium resonance doublet is one of the most sensitive 
indicator of such outflows. In several stars, the sodium D Na I lines have 
the P Cygni profiles with the very complex blue-shifted absorption consisting 
of a few narrow discrete absorption components (DACs). I argue in my talk 
that the most probable mechanism of formation of such DACs is the, so called, 
“propeller” mechanism. It is a result of interaction of circumstellar disk 
with the stellar magnetosphere. On the way to the Main Sequence, the 
efficiency of this mechanism has to increase with the mass accretion 
decrease.