Published online by Cambridge University Press: 14 March 2005
More than 30 active regions were observed on the Sun during October-November 2003 by SOHO. Approximately half of such regions induced hard X-ray and $\gamma$-ray emission and some solar flares with class M and X were detected during this time by GOES, RHESSI and other experiments. 5 solar flares were detected by AVS-F instrument onboard CORONAS-F satellite. Nuclear $\gamma$-emission lines were detected during some flares observed in this period, in particular, during all flares on October 29 2003.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html