Extreme Ultraviolet Imaging of Three-dimensional Magnetic Reconnection in a Solar Eruption

TL;DR

This study provides direct 3D observational evidence of magnetic reconnection in a solar eruption using EUV imaging from two spacecraft, revealing detailed plasma dynamics and magnetic topology changes.

Contribution

It is the first to observe and analyze magnetic reconnection in three dimensions during a solar eruption with multi-perspective EUV imaging.

Findings

Reconnection involves non-coplanar magnetic loops forming a separator.

Plasma heats from ~1 MK to ≥5 MK at the reconnection site.

Warm flare loops appear beneath hot plasma post-reconnection.

Abstract

Magnetic reconnection, a change of magnetic field connectivity, is a fundamental physical process in which magnetic energy is released explosively. It is responsible for various eruptive phenomena in the universe. However, this process is difficult to observe directly. Here, the magnetic topology associated with a solar reconnection event is studied in three dimensions (3D) using the combined perspectives of two spacecraft. The sequence of extreme ultraviolet (EUV) images clearly shows that two groups of oppositely directed and non-coplanar magnetic loops gradually approach each other, forming a separator or quasi-separator and then reconnecting. The plasma near the reconnection site is subsequently heated from $\sim$1 to $\ge$5 MK. Shortly afterwards, warm flare loops ($\sim$3 MK) appear underneath the hot plasma. Other observational signatures of reconnection, including plasma inflows and downflows, are unambiguously revealed and quantitatively measured. These observations provide direct evidence of magnetic reconnection in a 3D configuration and reveal its origin.