Flare Hybrids

TL;DR

This paper reviews the characteristics, observational signatures, and magnetic configurations of flare hybrids, a distinct class of solar flares that transition from compact to arcade-like structures, emphasizing their frequency and key features.

Contribution

It provides a comprehensive summary of flare hybrids, including their observational features, possible physical mechanisms, and magnetic configurations, highlighting their frequency and distinguishing parameters.

Findings

Flare hybrids exhibit two distinct phases observable in X-ray and EUV.

The difference in magnetic loop lengths is crucial for identifying flare hybrids.

Flare hybrids are quite frequent on the Sun.

Abstract

Svestka (Solar Phys. 1989, 121, 399) on the basis of the Solar Maximum Mission observations introduced a new class of flares, the so-called flare hybrids. When they start, they look as typical compact flares (phase 1), but later on they look like flares with arcades of magnetic loops (phase 2). We summarize the features of flare hybrids in soft and hard X-rays as well as in extreme-ultraviolet; these allow us to distinguish them from other flares. Additional energy release or long plasma cooling timescales have been suggested as possible cause of phase 2. Estimations of frequency of flare hybrids have been given. Magnetic configurations supporting their origin have been presented. In our opinion, flare hybrids are quite frequent and a difference between lengths of two interacting systems of magnetic loops is a crucial parameter for recognizing their features.