Observations of 8-kilogauss magnetic field in a sunspot

Abstract

The results of specrtal-polarized measurements of magnetic fields in two great sunspots are presented observed on 18 May 2002 and 29 October 2003 on horizontal solar telescope of Astronomical Observatory of Kyiv Taras Shevchenko National University. On a base of detailed study of the Zeeman splitting in FeI 6301.5 and 6302.5 lines, the following spectral effects were found in second spot: a) non-parallelism of bisectors in I+V і I-V profiles on distances about ±250 mÅ from line center of FeI 6301.5 and b) narrow and weak secondary peaks of Stokes V parameter on distances ±387 mÅ from center of FeI 6302.5 line. The conclusion is argued that these peculiarities indicate the presence in sunspot of subtelescopic magnetic field with strength about ≈8100 G which had the same polarity (N) as 3200 G background magnetic field of this sunspot.

Keywords

• sunspots
• magnetic fields