Measurements of stellar magnetic fields with FORS 1 in spectropolarimetric mode

In the last two years, the use of FORS 1 (FOcal Reducer low dispersion Spectrograph with polarimetric capability), mounted on the 8-m Kueyen telescope, led to a number of important advances in the studies of stellar magnetic fields. At the very beginning of these studies only the grism 600B was used with FORS 1 in polarimetric mode, providing the possibility to obtain both Stokes I and Stokes V as a function of wavelength in a spectral region from below the Balmer jump to Hβ. However, very useful circular polarimetry has also been obtained with grisms 600R, 1200G, and, very recently, with the grism 600I, which allows to study both the Ca II infrared triplet lines and the hydrogen Paschen lines. We describe here the recent scientific results achieved for studies of stellar magnetic fields using different FORS 1 instrumental settings.