Abstract:
Solution of line-transfer equation in the co-moving frame, obtained on the basis of discrete space theory, has been employed to calculate the lines emerging from a rapidly expanding stellar atmosphere. The solution is found to be highly stable for large velocities of expansion with both positive and negative velocity gradients. Profiles of spectral lines have been presented that are translated along the line of sight of the observer at infinity. A non-LTE two-level atom has been treated in a medium scattering isotropically with line and continuum emission P Cygni-type profiles noticed in a purely scattering medium.