An Example of the Correlation Between Energetic X-ray Flares and the Proper Motion of the Sunspots——The Analysis of Boulder Active Region 1994 (YAR 79455)

The analysis of the photospheric and chromospheric morphology of the active region shows that two x-class x-ray flares (which maxima reached at 2303UT on 19 Sept. and at 2303 UT on 22 Sept., respectively.) produced in the active tegion during its passage across the solar disk were closely correla ted to the motion with respect to the surrounding photosphere of the sunspots(proper motion).1. The growth of the spots near(<1.5")the magnetic reversed line made the maximum of the carvature (acute angle) of the reversed line reach, and a filament above this area disappeared on 19 Sept. The spots within the acute angle area (s polarity) produced a "daughter umbra", as a result, the reversed line was broken in the part of the curvature maximum, and then it connected with another magnetic reversed line near it on 22 Sept. This was accompanied with the occurrence of the first of the abovementioned x-ray events. 2. After the first flare, from 20 to 22 September, the daughter umbra began iti evident rotation in the counterclockwise direction. Its angular velocity was about 4°/hr. In the mean while, the two dipole spots in the middle fo the spot group rotated in the clockwise direction. Thus, the plasma in the areas between these rotating bodys (situated in the same penumbra) had the macroscopic horizontal velocities. Then, the filament above these areas was activated (or disappeared) firstly, after that, the second x-class x-ray event occurred.