Some comments on the east-west solar flare distribution during the 1976?1985 period

Abstract

We present the results of an analysis of the east-west asymmetry in the solar flare distribution, observed during the years from 1976 to 1985. We conclude that flare events, all type of Hα flares, are not uniformly spread in heliolongitude over the solar disc when considering events with heliolongitudes greater than 60°, or even closer to central meridian for certain periods. This lack of homogeneity, however, does not have an influence on the definition of east-west asymmetries. Simple random distribution of flares over the solar disc can not account for the asymmetries found, but they can be explained in terms of the transit of ‘active regions’ in front of the observer's position. Nonetheless, this is not the case for the distribution of flares equal or more intense than importance 1F observed during 1979.