Evolution of Balmer-line emission profiles of V1500 Cygni in the early decline phase

The emission lines of the hydrogen Balmer series, during much of the early decline phase, consist of four major components whose relative intensities evolve with time. The evolution of the major components of the lines with time is examined in this paper in terms of a simple parameterization scheme involving four identical condensations which radiate anisotropically. The parameterization describes the evolution of the major components quite well, and leads to the conclusion that the anisotropy of the radiation from the condensations is the most important parameter, and that geometrical parameters (such as the inclination of the system and the condensation size relative to the system size) are probably relatively model independent. The anisotropic radiation from each condensation is suggested to be a consequence of their being partially ionized.