Observations of the Onset and Launch of a Pre-Existing CME Flux Rope

We present a narrative of the launch and early evolution of a flux rope that formed the coronal mass ejection (CME) of 12 December 2008. The flux rope was present prior to launch, indicating that in this case it did not form during the launch process. We find that a sequence of seemingly separate CMEs observed in the corona and solar wind were actually manifestations of the same flux rope, demonstrating that coronagraph observations of multiple CMEs can, and we speculate often are, the same physical phenomena (flux rope) observed at an angle relative to the observer. The launch begins with a small solar flare at the northern-most end of the flux rope, which lifts off from this end first via the tether-cutting onset mechanism. Other segments of the flux rope follow this launch, and a filament is observed to roll over the top of these segments and pour back into the solar disk, which is indicative of the mass draining mechanism. The southern end of the flux rope remains fixed to the Sun, leading to an eventual stress-fracture and probable bisection of the flux rope. The severed southern end eventually disconnects from the Sun a day later via what appears to be the kink instability mechanism. The launch of the complete flux rope therefore involved the interplay between three separate onset mechanisms for this simple CME during a period of extremely low solar activity.