A giant of its kind, this huge prominence was glimpsed through heavy cloud. Over 100Mm high it was clearly erupting off the disc - and did so some hours later - resulting in a small CME that was not 'geoeffective'. The logs from 14 days earlier showed a hedgerow at the western limb with the same coordinates as shown above. The eruption caused the two foreground filament to vanish also.
Five NSO GONG images (c) show September's big filament as it crosses the sun - for the second time!
These five GONG views show the filament tilted from our line-of-sight in views 1, 3, 4 and 5. Note how different it looks as the l-o-s changes: showing complex details of the footpoints.View 2 shows it crossing the central meridian: we see it from directly overhead. Fig 5 shows it at the moment of lift off. It ejected at 900km/s, causing widespread aurorae on planet Earth. Heliocentric positions show it had made almost 2 complete rotations of the Sun at the time of liftoff! A very long-lived filament. In the process, H-alpha users saw some great prominences. Will the filament reform at the site?