Role of Chromospheric and Coronal Ejections in the Development of LDE Flares in the Sun

Abstract

Based on observations in the Hα and extreme ultraviolet lines, as well as in the radio and X-ray wavelengths, we study the eruptive events of September 22 and 24, 2011, that occurred in the active region (AR) NOAA 11302. It has been found that a complex magnetic configuration has formed as a result of appearance of new bipolar sunspots near the tail sunspots. From the comparison of two long flares, it follows that they were related to high-energy coronal mass ejections (CMEs), whose eruption mechanisms differed significantly at the level of the chromosphere and the lower corona. In the case of September 22, repeated eruptions of prominences before the CME took place, while on September 24, recurrent jets were observed before and after the CME. In both cases, a CME merging could take place, after which the precipitating substance led to the development of long flares in the soft X-ray range and the formation of a post-eruptive arcade, which was clearly visible in the extreme ultraviolet lines.