Solar Filaments: `Shake, Rattle & Roll'

Solar filaments, the spectacular cloud-like and multi-threaded condensations in the million degree solar atmosphere, demonstrate so-called `large amplitude oscillations' (or LAOs): they are seen to sway back and forth with speeds exceeding 10-20 km/s. Recently, solar physicists published the first systematic catalog of filament oscillations that occurred within a half year period of the previous solar maximum: almost 200 events could be detected by visual inspection of historic data. The filament `shakes' come in various flavors: small and large amplitude ones, as well as displacements that are aligned (longitudinal) or perpendicular (transverse) to the overall filament body. The longitudinal versions repeat their `rattling' motion every hour, and this can be understood using a simple pendulum analogue where the filament matter bounces back and forth in a dipped magnetic field. LAOs are induced by nearby solar flares or jets, and sometimes seem to make the filament threads `roll' over. Starting from their recent jointly published 3D numerical simulation model of solar filament LAOs, KU Leuven and Nanjing University now join forces to tackle the remaining mysteries of the filament `Shakes, Rattles & Rolls'. How do the large amplitude motions damp out, how are they excited, and what is the role of the multi-threaded fine structure in filament LAOs?