Observation of An Evolving Magnetic Flux Rope Prior To and During A Solar Eruption

TL;DR

This paper reports the observation of a hot, twisted magnetic flux rope that evolves and triggers a solar eruption, providing new insights into the eruption mechanism beyond traditional magnetic reconnection theories.

Contribution

It demonstrates the critical role of magnetic flux rope instability in solar eruptions, challenging the traditional magnetic reconnection paradigm.

Findings

Magnetic flux rope appears as a hot, twisted sigmoidal structure before eruption.

The flux rope transforms shape during a slow rise phase before rapid acceleration.

Flux rope instability likely triggers the solar eruption.

Abstract

Explosive energy release is a common phenomenon occurring in magnetized plasma systems ranging from laboratories, Earth's magnetosphere, the solar corona and astrophysical environments. Its physical explanation is usually attributed to magnetic reconnection in a thin current sheet. Here we report the important role of magnetic flux rope structure, a volumetric current channel, in producing explosive events. The flux rope is observed as a hot channel prior to and during a solar eruption from the Atmospheric Imaging Assembly (AIA) telescope on board the Solar Dynamic Observatory (SDO). It initially appears as a twisted and writhed sigmoidal structure with a temperature as high as 10 MK and then transforms toward a semi-circular shape during a slow rise phase, which is followed by fast acceleration and onset of a flare. The observations suggest that the instability of the magnetic flux rope trigger the eruption, thus making a major addition to the traditional magnetic-reconnection paradigm.