A Preliminary Survey of the Zeeman Effect in the Sun-Spot Spectrum

Abstract

view Abstract Citations (9) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Preliminary Survey of the Zeeman Effect in the Sun-Spot Spectrum King, Robert B. Abstract A preliminary study of the Zeeman effect in the sun-spot spectrum based on Mount Wilson plates and mostly on measures made at Mount Wilson and lent to the author. The spectrograms include observations on six different spots. Since no common deter- mination of field-strength by means of the iron line X 6i 73 was available, the spectral re- gions from different spots have been treated separately. A blending effect, probably caused by the inclination of the lines of force in the spot to the line of sight, which tends to reduce the apparent field-strength, is revealed by fre- quency distribution-curves of the apparent field-strengths shown by different lines. This effect is at a maximum in the violet and a minimum in the red. A "selected list" of 416 lines has been prepared for which this effect should be much diminished. The apparent correlation between spot intensity of lines and field-strength is con- firmed for the average of all lines, the field-strength decreasing with increasing line in- tensity. The correlation is much weaker for the selected lines to the violet of X 6ooo, and vanishes for those to the red. Complicated effects of blending and observational selec- tion leave the question of correlation between true field-strength and line intensity an open one. Enhanced lines give smaller field-strengths than arc lines of the same spot intensity. A correlation between Evershed effect and field-strength is found for 258 lines; but Evershed effects are found to be more closely correlated with disk intensities, while field-strengths are better correlated with spot intensities. The question of variation of field-strength with level is discussed. The relative levels of different elements indicated by the field-strengths found from lines of the same spot intensity differ somewhat from those of St. John based on disk intensities. Allowance for intensity differences between disk and spot spectra improves the agreement. No relation has been found between the field-strength or the character of the Zeeman patterns and the noteworthy strengthening in the spot spectrum of faint sateffite lines in many multiplets. INTRODUCTIO Publication: The Astrophysical Journal Pub Date: September 1934 DOI: 10.1086/143589 Bibcode: 1934ApJ....80..136K full text sources ADS | Related Materials (1) Reprint: 1934CMWCI.497....1K