The 'mega-cool' filament is not visible anymore. It lasted for 2 solar rotations.
In the month February, an extremely large filament was visible on the solar disk. The black line in the left H-alpha picture, taken by the ground-based observatory in Catania, represents this plasma cloud. It rotated again over the east limb during the first part of March: on March 14, it was again clearly visible in the H-alpha pictures. In the picture the most at the right, taken on April 11, the filament is not present any more as a whole, only a small part, hardly visible remained.
