The Pre- and Post-Launch Configuration of a CME Flux Rope

Abstract:

While the standard picture of a coronal mass ejection (CME) remains largely unchanged from the early 1990s, we continue to develop our understanding of the finer structures comprising the CME anatomy. Our efforts are impeded by an assortment of inconveniences involving the detection and tracking of CMEs: namely that they are two-dimensional manifestations of an extended three-dimensional structure, they are optically-thin, have asymmetric geometries that evolve at different kinematic rates, and when observed by coronagraphs their appearances are subject to the laws of Thomson scattering. Even in the STEREO era we have rarely had an opportunity to explore in 3-D the finer structures comprising CMEs and their greater counterparts. Through careful analysis of a CME observed during such an opportunity, we have constructed a detailed narrative describing the pre-launch configuration of the magnetic configuration that gave rise to the CME, and its launch and evolution through the corona and solar wind. We present our narrative using observational evidence from EUV imagers, coronagraphs and heliospheric imagers. We offer insight into the implications of its 3-D structure for CME observation, including the difficulties presented by geometry, kinematics and Thomson scattering.