Ha filtergrams of the chromosphere show an emission rim in many hydrogen filaments. We suppose that formation of this rim is due to photospheric radiation reflected by the filament in the direction of the chromosphere. The calculations show that: (1) the maximum contrast of the rim relative to the undisturbed chromosphere amounts to 1.4; (2) the larger the optical thickness of the filament and the closer to the solar limb it is situated, the brighter and wider is the rim; (3) the rim was not observed in filaments whose heights exceeds 10000 km above the chromosphere. These results are in close agreement with observations.
The shifts of Fraunhofer lines of different chemical elements in a homogeneous medium with a plane monochromatic progressive adiabatic sound waves are derived. The calculations indicate that lines of neutral elements (6 ~< ;go ~< 14) with lower excitation potentials Zo~ = 0-2 eV are red shifted, those with excitation potential Z0.z = 4-12 eV are blue shifted, and with Z0~ = 3 eV are both blue and red shifted. The lines of ions are shifted toward the blue. The shifts of Fraunhofer lines are found to decrease from the centre of the solar disk to the limb. These results agree qualitatively and quantitatively with observations.
All analysis is made of the as3mmetry of Fraunhofer lines observed with the double-pass monochromator of the horizontal solar telescope ASU-5 of the Main Astronomical Obserx atory of thc Ukrainian Academy of Sciences. The conclusion is that the character of macromotion in the radial direction varies with height; in a tangential direction the motions at diflerent depths are homogeneous. The asymmetry of weak lines is due to convection rather than to wave motions.
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