The Solar Magnetic Field and Coronal Dynamics of the Eruption on 2007 May 19

Abstract

The solar eruption on 2007 May 19, from AR 10956 near solar disk center, consisted of a B9.5 flare (12:48 UT), a filament eruption, an EUV dimming, a coronal wave, and a multifront CME. The eruption was observed by the twin STEREO spacecraft at a separation angle of 8.5deg. We report analysis of the source region photospheric magnetic field and its preeruption evolution using MDI magnetograms, the coronal magnetic field topology estimated via PFSS modeling, and the coronal dynamics of the eruption through STEREO EUVI wavelet-enhanced anaglyph movies. Despite its moderate magnitude and size, AR 10956 was a complex and highly nonpotential active region with a multipolar configuration, and hosted frequent flares, multiple filament eruptions, and CMEs. In the 2 days prior to the May 19 eruption, the total unsigned magnetic flux of the region decreased by ~17%. We interpret the photospheric magnetic field evolution, the coronal field topology, and the observed coronal dynamics in the context of current models of CME initiation and discuss the prospects for future MHD modeling inspired by these analyses.