THE PERIODICITY OF AR5395 EVOLUTION

There are periodical characteristics in the evolution of AR5395 shown by analysing the observational data of X-ray flares and area of sunspot group. Fod AR5395 the variation of peak flux F_x of soft X-ray exhibits a periodicity about 24.3 hours, the periodicity for the occurrence rate N_x of X-ray flares is about 12.2 houds, and the area S_x of sunspot groups varies with 24.4 hours period. The phase relations among these three periodical parameters show: (1) the flares with Xclass generally appears at the decreasing phase of the peridlical variation of sunspot area; (2) the area of sunspot groups takes about 16 hours to reach the maximum in the 24.4 hours period; (3) the rate of occurrence of X-ray flares reaches the maximum before the appearance of Xclass flare about 12 hours. It seems that AR5395 is in a state of energy store-release-store cycle of large flares with a periodicity about 24 hours.