Depression variability at 5200 in the β Lyr and ν Sgr spectra

Using the absolute spectrophotometrical data on binary stars β Lyr and ν Sgr the variability of depression at lambda 5200 dependent on the phase of orbital cycle has been studied. The variations of the equivalent width of the depression in the spectrum of β Lyr correlate with the magnetic field variations. The magnetic field strength of ν Sgr is predicted to be > or approximately 4 kGs