The Evolution of Two Recurring Flares Into an Active Region

The authors study the morphological evolution in time and space of two "homologous" flares into an active solar region. This complex region of high activity has produced during its lifetime many flares of different importance. The region was photographed at 08:33 UT on April 15, 1969 in H-alpha through a monochromatic filter. A long sequence of 600 filtergrams obtained with the 40 cm refractor of the National Observatory of Athens permitted to study the entire evolution using methods of photometric analysis.