The light curve describes the trend of the average brightness of the solar disk of the recorded H Alpha images. The signal is normalized by the exposure time. The light curve takes into account the approximation model for solar intensity vs air mass proposed by Meinel & Meinel (1976). The air mass as function of the zenith angle of the Sun has been computed by the model of Kasten & Young (1989).
The images are stored thanks to the support of the Italian Center for Astronomical Archives of INAF.