ESPriF: the Echelle Spectropolarimeter of the BTA Primary Focus. Correction of Low-Frequency Variations in the Star Image

The development of a corrector for low-frequency variations in the star image at the input of ESPriF, the echelle spectropolarimeter of the BTA primary focus, is reported. New technical solutions have made it possible to extend the operating frequency range to 10Hz for stars brighter than 13^m.