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The present study continues the investigation of the super-fast variability of line profiles in the spectra of stars of early spectral types. We studied the line-profile variability in the spectrum of the binary (O9.7Ib+B0III) star Ori A using the MSS spectrograph of the 6-m BTA telescope based on observations carried out on February 19, 2019. Short-period regular variations of the hydrogen Balmer lines and He I lines with periods from 89 to 295 minutes were found. The presence of short-period variations in the period interval of 10-20 minutes is also possible. An analysis of the stellar brightness variations from observations by the TESS satellite showed the presence of seven regular components, one of which is probably the second harmonic of the rotation period of the main component of the Aa star Ori A. The magnetic field of the star was determined for the whole series of observations. The longitudinal component of the root-mean-square magnetic field measured by the regression method over the whole observation period is G.

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New results of studying the variability of line profiles in the spectra of bright OBA stars on minute and second time scalesare presented. The observations were carried out in 2015–2021. Nearly 11000 spectra of 22 OBA stars were obtained. Regularvariations of the line profiles with minute periods and amplitudes of 1–2% of the continuum level in spectra of the programstars are found.

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