Rotation of sunspots in active region NOAA 10930

The rotation of sunspots of the active region NOAA 10930 has been investigated using a time series of vector magnetic field maps from the Solar Optical Telescope aboard Hinode. The vertical, radial and azimuthal axisymmetrical components of the magnetic field vector have been reconstructed from the magnetic field line-of-sight component for both sunspots of this active region. The existence of an azimuthal field component means that the magnetic field lines are twisted. The azimuthal components of both sunspots are of same sign. The magnetic flux tubes which form the sunspots of the active region on the solar surface are twisted clockwise. The vertical electric currents generated as a result of rotation and twisting of the magnetic flux tubes have the same direction.