VELOCITIES AND MAGNETIC-FIELDS OBSERVED IN A SUNSPOT

A diagnostic method for the determination of the vector magnetic field through the interpretation of spectropolarimetric profiles observed in solar active regions is presented. An inversion routine, that is based on the analytical solution of the radiative transfer equation for polarized radiation given by Unno and Rachkowsky, is described; the routine performs a comparison among theoretical profiles depending on eight parameters and the observed profiles by means of a non linear least square fit. The routine has been applied to the interpretation of the spectropolarimetric profiles observed on 15 September, 1980 in a sunspot with the spectropolarimeter (Stokes II) of the High Altitude Observatory, National Center for Atmospheric Research*. One of the eight parameters (the line center) gives information on the plasma motions. The significance of these motions inside the sunspot is discussed. © 1990 Kluwer Academic Publishers.