Light curves for different segments of the Hα (top) and Hβ (bottom) broad emission lines. The line-segment fluxes are given in 10^-14 and 10^-15   erg   cm^-2   s^-1 for Hα and Hβ, respectively, while the date is given in the modified Julian Date as MJD = JD-2400000.5. The mean velocity for the segment number is: (± 4) corresponds to (± 8500) km  s^-1; (± 3) corresponds to (± 6000) km  s^-1; (± 2) corresponds to (± 4000) km  s^-1; (± 1) corresponds to (± 2000) km  s^-1; 0 corresponds to (1000) km  s^-1. The blue part is denoted with crosses, the red part with pluses, and the line core with full circles. The solid line represents the continuum flux in arbitrary units for comparison.