Oscillating filament

When a filament reaches the limb (due to solar rotation) by convention it changes its name to a "prominence" (a generic term for any thing above the limb). This is historic but confusing- so I won't use it here. The Fig shows a very bright filament at the limb that over some hours underwent dramatic changes.  "Animate" the view and we see first the bright south-side arch (lhs) rise while the north remains low then, view e, the south side falls while the north rises higher as a faint but active arch: a rocking or oscillating motion (N is to right)
      The filament's 13 degree N latitude puts it in the zone of current active regions (aka sunspots) but none were nearby in longitude (223).  (CORRECTION: the filament was probably part of AR11476. This group's (p) spot had longitude 190 degrees. It seems  the filament was part of this group, despite the 30 deg logitude difference. Lines of longitude crowd together near the limb).  This event was on May 1 (UT as shown) and the filament reached ~120Mm in length - at its brightest (a and b) it equalled the disc (the chromosphere) c to g in parts ~ 0.5 disc, i.e. very bright.