Bulletin of Taras Shevchenko National University of Kyiv. Astronomy, no. 55, p. 34-39 (2017)
Magnetic field measurements in sunspots using spectral lines with different Lande factors
V. Lozitsky, Dr. Sci.,
Astronomical Observatory of Taras Shevchenko National University of Kyivб, Kyiv
S. Osipov, Ph. D.,
Main Astronomical Observatory of National Academy of Science of Ukraine, Kyiv
Abstract
Results of direct measurements of magnetic fields in sunspots are presented. Observations were carried out in June-July 2015 on Horizontal Solar Telescope AtsU-5 of Main Astronomical Observatory of National Academy of Science of Ukraine. Magnetic fields were measured by the Zeeman splitting of some spectral lines of FeI, MnI and NiI placed nearly FeI 5434.5 Ǻ and FeI 6093.66 Ǻ. Effective Lande factors of these lines, geff, are in range from – 0.22 до 2.14. Significant differences were found both for lines with different and closest values of geff. In some places of sunspots, FeI 5434.5 Ǻ line (geff = – 0.014) displays a realible splitting which corresponds to magnetic field strengths up to 2.5 kG. In all cases under study, FeI 6094.419 Ǻ line with negative Lande factor (geff = – 0.22) has the sign of splitting as a line with positive Lande factor (geff > 0). The possible reasons of this effect are discussed.
Key words
Sun, sunspots, Zeeman effect, magnetic fields, direct measurements, Lande factors
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