A large flare-associated filament in september 1989

The behaviour of a long-lived extended filament in active region NOAA 5669 with a complex magnetic structure has been followed. The relation between the filament behaviour and flare activity in September 1989 has been investigated. The filament was quiet when flares were generated in the inner parts of the active region. Some matter layers were separated from the parent filament and erupted when flares occurred near the rooted end of the filament.