Eruption of a Kink-Unstable Filament in Active Region NOAA 10696

Abstract

We present rapid-cadence Transition Region And Coronal Explorer (TRACE) observations which show evidence of a filament eruption from active region NOAA 10696, accompanied by an X2.5 flare, on 2004 November 10. The eruptive filament, which manifests as a fast coronal mass ejection some minutes later, rises as a kinking structure with an apparently exponential growth of height within TRACE's field of view. We compare the characteristics of this filament eruption with MHD numerical simulations of a kink-unstable magnetic flux rope, finding excellent qualitative agreement. We suggest that, while tether weakening by breakout-like quadrupolar reconnection may be the release mechanism for the previously confined flux rope, the driver of the expansion is most likely the MHD helical kink instability.

Accepted by ApJ Letters. 4 figures (Fig. 3 in two parts). For MPEG files associated with Figure 1, see: http://www.mssl.ucl.ac.uk/~drw/papers/kink/ktrace.mpg http://www.mssl.ucl.ac.uk/~drw/papers/kink/kmdi.mpg http://www.mssl.ucl.ac.uk/~drw/papers/kink/ksimu.mpg