... SHTOL ' Special Astrophysical Observatory of the Russian AS, Nizhnij Arkhyz 357147, Russia The investigation of such a phenomenon as the magnetic field variability at long times (years - decennials) is very interesting. If the explanation of the magnetic field variability with rotation period by the oblique rotator model is evident, then the reason of the long-period variability is not clear yet, despite the existence of some assumptions on its nature. ... Fig.2. ... 213 Fig.3. ...

... As a result of BTA observations of 23 chemically peculiar stars with strong magnetic fields, it was found that in 22 of them the longitudinal magnetic field, measured from the hydrogen line cores are considerably lower (by about 1/3) than the value measured from metal lines in the same spectra. ... New approaches need to be developed in order to interpret the data. ... The Zeeman spectrum of a star with a strong magnetic field, 53 Cam. ...