The Axial Distribution of the Rotational Velocity of a Sunspot Filament

The distribution of the. rotational angular velocities, the integral translat-ional velocities and the radii along the filamentary axes of six different sunspot filaments are given in this paper. The results show that the rotational direction of a shorter active filament does not alter along the axis, and that the angular velocity varies monotonously, it can change the winding state of the filament and is a possible mechanism of producing the macroscopic unstability of prominence plasma. And the winding structure of a longer quiet filament may exist, the motion of the filament is comparatively complex and the rotational direction alters along the axis. But there seems to be a positive correlation between the integral radial velocities and the rotational angular velocities of the two kinds of filaments. Finally, the rotational kinetic energy is also estimated.