AR5395活动区演化的周期性

观测资料分析表明,AR5395活动区演化具有周期性的特征,软X射线峰值流量F变化周期为24.3小时,X射线耀斑出现率N_x,具有12.2小时的周期性,活动区黑子群面积S_x的变化呈现24.4小时的周期。这3个周期变化量的相位关系表明:(1)X级耀斑往往发生在黑子面积减小的位相;(2)在1个周期内,黑子群面积达到最大值约需16小时,恢复到大耀斑前水平约需8小时;(3)在X级大耀斑前约12小时,小级别耀斑出现率达到峰值。分析显示,AR5395活动区似乎工作于大耀斑能量储存—释放—储存周期性循环的极限状态之中。 

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 Fx of soft X-ray exhibits a periodicity about 24.3 hours, the periodicity for the occurrence rate Nx of X-ray flares is about 12.2 houds, and the area Sx of sunspot groups varies with 24.4 hours period. The phase relations among these three periodical parameters show: (1) the flares with X class 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 X class 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.