On the evolution and flare activity of the sunspot group on July, 1978

On the basis of the original photoheliograms, Hsub(α)- filtrograms and wide-band films, obtained in Tashkent, the evolution of the sunspot group, which had delta-configuration and passed on July 8-21, is studied. In the active region (AR) which includes the sunspot group, according to Solar Geophysical Data, more than 160 Hsub(α) flares were observed. The comparison of the evolutionary changes of the group and the flare activity of the AR revealed the following: the flare acivity was caused by the formation of the new sunspots group inside the old one. The new umbrae form along the neutral line of the longitudinal magnetic field of the group. The knots of the majority of the flares are situated along the neutral line and not far from the new umbrae. The total area of the group fluctuated near its mean values. Some of the new umbrae show a systematic proper motion with a velocity approximately 0.5 km/s and others show an uneven motion, which is similar to throbbing: all the motions were directed away from the old group, as a result of the new umbrae evolution near the old umbrae, small of them break up, the large umbra boundary near to the new umbrae deforms and inside the large umbra the umbral dots were burned