STUDIES OF FLARE-ASSOCIATED FILAMENT PHENOMENA.

A study was made of the phenomena most frequently observed to occur or change preceding or accompanying the development of major flares. The changes referred to are only those occurring in the immediate vicinity of the flares and within two hours preceding the start of the flares. The frequency of occurrence of the observed changes were analyzed as a function of the time of occurrence relative to flare start, the wavelength of the observations, and the position on the solar disk. Preflare changes in absorption features were found to follow a definite statistical pattern. Two other events or changes were found to occur frequently within the same time interval as the pattern of changes in absorption features. These are 1 preflare brightenings and 2 bright andor dark ejective phenomena.