The Phenomena of Flares and CMEs in the Sun and Stars: Why Are the Energy Upper Limits in Both Phenomena Comparable?

Abstract

Abstract Solar/stellar flares which release large energies occur less frequently than those with small energies. Flare energies on a given star have not (yet) been observed to exceed E fm . Similarly, coronal mass ejections (CME’s) with large kinetic energies (KE) on a given star also occur less frequently than those with small energies. The KE's of CME’s on a given star have not (yet) been observed to exceed KE m . Interestingly, in any given star, E fm is found to be comparable in magnitude to KE m . This is puzzling since a one-to-one correlation between flares and CME’s does not exist: some flares occur without any accompanying CME, and some CME’s have no accompanying flare. Moreover, different types of MHD instabilities are believed to give rise to flares and CME’s. The result E fm ≈ KE m could indicate support for Bemporad’s conclusion: magnetic energy in the corona is in global equipartition with gravitational potential energy.