Solar microflares are ubiquitous in the solar corona, yet their driving mechanisms remain a subject of ongoing debate. Using high-resolution coronal observations from the Solar Orbiter's Extreme Ultraviolet Imager (EUI), we identified about a dozen distinct moving plasma structures (hereafter, `` tiny ejections'') originating from the centers of three homologous microflares out of four successive events. These tiny ejections propagate roughly perpendicular to the flaring loops. They often originate as dot-like structures with a length scale of approximately 103 km. While these initial dot-like shapes are observable in EUI images, they remain undetectable in the images captured by the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory. As they propagate, these dot-like structures consistently evolve into loop-like formations, possibly due to the heating of the surrounding magnetic field. Rather than being generated by a series of flux rope eruptions, the tiny ejections appear to result from small-angle magnetic reconnections within a bipolar field. Thus, the microflares associated with these ejections may be driven by magnetic reconnection within braided fields, a process similar to the proposed nanoflare mechanism and distinct from the standard large-scale flare model.
@article{arxiv.2503.11459,
title = {Moving Plasma Structures and Possible Driving Mechanisms of Solar Microflares Observed with High-Resolution Coronal Imaging},
author = {Qingmei Wang and Yi Bi and Hongfei Liang and Jiayan Yang and Liufan Gong},
journal= {arXiv preprint arXiv:2503.11459},
year = {2025}
}