S320.5.04 — Too big to fail: The role of magnetic structure and dynamics in super active regions, on the Sun and Sun-like stars

Date & Time

Aug 12th at 11:14 AM until 11:26 AM




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Author(s): R.T.James McAteer1

Institution(s): 1. New Mexico State University

Accurate and timely solar activity forecasting has proved to be illusive. Despite many decades of research, we are not much further advanced in our forecasting efforts of the occurrence of solar activity than we were two decades ago. However, one aspect has become clear - big, complex magnetic active regions on the Sun inevitably produce big, complex solar flares and coronal mass ejections. Here, I present observations and models that show why these super active regions are too big to fail.
First I focus on studies of the largest active regions of solar cycle 23 and 24, comparing proxies of non-potential magnetic structure in these regions with similar proxies in less active regions of the Sun. This shows that the necessary and sufficient conditions exist in these super active regions to provide both the largest solar flares and large, fast, coronal mass ejections.
Second I show why these conditions in super active regions differ so dramatically from the conditions in smaller, less active, regions of the Sun. This uses magnetic feature tracking to infer the Poynting flux injected into the corona, and DEM analysis to provide radiative and conductive loss estimates from the corona. The difference between energy injected, and energy lost, is stored in the coronal magnetic field structure in the super active regions.
Finally, I apply this this research to Kepler starspots , showing why these regions must differ in a fundamental way in order to overcome the limitations that super granular flow places on solar active regions formation and energy storage.