ПРИХОВАНІ ПРОЯВИ ЕФЕКТУ ПАШЕНА – БАКА В ЛІНІЯХ D1 і D2 У СПЕКТРІ СОНЯЧНОЇ ПЛЯМИ БЕЗ СПАЛАХІВ

Abstract

The results of measurements of the magnetic splittings of the D1, D2, and Ni I 5892.9 Å lines in the spectrum of the sunspot on July 24, 2023, in which there were no solar flares at the time of observation, are given. The observational material was obtained with the Echelle spectrograph of the horizontal solar telescope of the Astronomical Observatory of Taras Shevchenko Kyiv National University. It turned out that in some locations of the sunspot, the measured spliting of the specified lines are practically the same, and in others they are significantly different. This indicates the inhomogeneity of the magnetic field, because with a uniform field, these splitting should differ everywhere by the same amount, depending on the Lande factors of these lines. If we assume that these factors correspond to LS coupling for all lines, then we have the following contradiction: the photospheric line NiI 5892.9 Å shows a magnetic field intermediate in magnitude between lines D1 and D2. Physically, this is unreal in the case of a uniform magnetic field; if the magnetic field weakens with height, then the nickel line should show a stronger field than both sodium lines. More realistic estimates of the magnetic field are obtained with empirical Lande factors for lines D1 and D2, corresponding to the Paschen-Back effect in these lines. However, even in this case, line D2 with a smaller Lande factor (gemp = 1.22) shows a stronger measured magnetic field in some places of the spot than line D1 with a larger Lande factor (gemp = 1.36). This is possible when the local magnetic fields in the studied spot were much stronger than according to direct measurements. Evaluation of such fields can be carried out on the basis of modeling by the “line ratio” method, which is planned to be done in the next study.