A study of the patterns of activity complexes of activity (CA) on the Sun at the growth 25th activity cycle has been completed. CA catalog has been compiled. During the first five years of the cycle from 1188 activity regions, observed on the Sun, 652 (54.8%) were part of CA. During the study period, a total of 76 CA were identified: 38, in the northern and southern hemispheres of the Sun, respectively. Duration of existence of the CA existence did not exceed 11 solar rotations. It was shown that 93% of X-ray flares of class X occurred in active regions located in CA. During the first five years of the 25th cycle there were three times more X-flares in the CA than during the same period in the 24th cycle. In the current cycle CA developing relatively symmetrically relative to the solar equator.
Yazev et al. (Mon,) studied this question.