Linking Solar Magnetism, Extreme Solar Particle Events and Stellar Superflares

TL;DR

This paper explores the potential physical connections between extreme solar particle events, superflares on Sun-like stars, and the underlying magnetic mechanisms, using historical, observational, and theoretical insights.

Contribution

It reviews current evidence and discusses possible physical mechanisms linking solar and stellar magnetic activity extremes, highlighting their complex relationship.

Findings

Superflares and ESPEs are both driven by magnetic energy release.

Their relationship is not strictly one-to-one, indicating different energy partitioning.

Magnetic flux and topology influence the energy distribution in eruptions.

Abstract

The magnetic field of the Sun drives a wide range of eruptive phenomena, from small-scale nanoflares to large flares and coronal mass ejections (CMEs). While direct observations of solar activity cover only the past few decades, indirect evidence indicates that the Sun can occasionally produce events orders of magnitude stronger than any recorded ones in the modern era. Two complementary lines of evidence exist. First, extreme solar particle events (ESPEs) have been inferred from prominent spikes in cosmogenic isotope concentrations preserved in precisely dated natural archives such as tree rings and ice cores over the past 15 millennia. Second, high-precision space-borne photometry has revealed superflares on thousands of stars similar to the Sun. Whether these solar and stellar extremes are physically related remains an open question. We summarise the present state of understanding and discuss physical mechanisms that may link them. Although superflares and ESPEs are both extremely energetic manifestations of magnetic energy storage and release, their relationship does not appear to be one-to-one. Their occurrence and energetics likely depend on how magnetic flux and topology govern the partitioning of released energy between radiation, mass ejection, and particle acceleration.