We present the results of a study of the temporal behaviour of several diagnostic lines formed in the region of the accretion-disk/star interaction in the three magnetic Herbig Ae stars HD 101412 , HD 104237 , and HD 190073 .
More than 100 spectra acquired with the ISAAC , X-shooter , and CRIRES spectrographs installed at the VLT-8m telescope ( ESO , Chile ) , as well as at other observatories ( OHP , Crimean AO ) were analyzed .
The spectroscopic data were obtained in the He i \lambda 10830 , Pa \gamma and He i \lambda 5876 lines .
We found that the temporal behaviour of the diagnostic lines in the spectra of all program stars can be widely explained by a rotational modulation of the line profiles generated by a local accretion flow .
This result is in good agreement with the predictions of the magnetospheric accretion model .
For the first time , the rotation period of HD 104237 ( P _ { rot } = 5.37 \pm 0.03 days ) , as well as the inclination angle ( i = 21 ^ { \circ } \pm 4 ^ { \circ } ) were determined .
Additional analysis of the HARPSpol spectra of HD 104237 and HD 190073 , taken from the ESO archive , with the use of the SVD method shows that the magnetic field structure of HD 190073 is likely more complex than a simple dipole and contains a circumstellar component .
For the first time , the magnetic field of the secondary component of the binary system HD 104237 was also detected ( \left < B _ { z } \right > = 128 \pm 10 G ) .