  We study the resonance line emission from the rotating plane optically thick
accretion disc, consisting of free electrons and resonant atoms. We use the
standard assumption that the source of continuum radiation is located near
central plane of the accretion disc, where the temperature is the highest. This
corresponds to the Milne problem consideration for continuum. We shortly
discuss the impossibility of the Milne problem for the resonance radiation. We
assume that the resonant atoms are located in a thin layer of an accretion disc
near the surface. In this case the resonance line emission arises due to
scattering of a continuum on the resonant atoms. In thin layer we can neglect
the multiple scattering of the resonance radiation on the resonant atoms. We
consider the axially symmetric problems, where the Stokes parameter U =0. We
take into account the Doppler effect for the frequencies of the resonance line.
The three types of the resonant atom sources are considered (see Figs.1-3). The
first source is the axially symmetric continuous distribution of the resonant
atoms along the circular orbit. The second spot-like source rotates in the
orbit. The third type presents two spot-like sources located in the orbit
contrary one to another. In the first and third cases the shape of the emitting
resonance line is symmetric, i.e. the right and left wings have the similar
shapes. In the second case the resonance line has asymmetric shape. The shape
of the emerging line depends significantly on the ratio of the rotation
velocity value to the velocity, characterizing the Doppler width. It also
depends on the ratio of the electron number density to the number density of
resonant atoms. The results of the calculations characterize the different
observational effects of H$\alpha$ radiation in the accretion discs and can be
used for estimations of the parameters mentioned above.
