Flyng-spot analysis of solar images

This work has been performed to test the new and interesting results obtained previously with a photographic isodensitmetric method about the photometric evolution of solar flares (Falciani et al., 1972; Falciani and Rigutti, 1972 a,b) and to study the degree of utility and reliability, and the general performances of high speed, computer controlled devices in the photometric analysis of extended sources. We studied some series of good Ha solar filtergrams, obtained during 1969 (May 15-16-17-25 and Oct. 25-27), at the Athens National Observatory (we warmly thank Dr. C.J. Macris for having kindly put at our disposal such a material), with time resolution of about 30 sec, with uniform exposure and high photometric accuracy (~5000 filtergrams).