A Circular White-Light Flare with Impulsive and Gradual White-Light Kernels

Abstract

White-light flares are the flares with emissions visible in the optical continuum. They are thought to be rare and pose the most stringent requirements in energy transport and heating in the lower atmosphere. Here we present a nearly circular white-light flare on 2015 March 10 that was well observed by the Optical and Near-infrared Solar Eruption Tracer and Solar Dynamics Observatory. In this flare, there appear simultaneously both impulsive and gradual white-light kernels. The generally accepted thick-target model would be responsible for the impulsive kernels but not sufficient to interpret the gradual kernels. Some other mechanisms including soft X-ray backwarming or downward-propagating Alfven waves, acting jointly with electron beam bombardment, provide a possible interpretation. However, the origin of this kind of white-light kernels is still an open question that induces more observations and researches in the future to decipher it.

23 pages, 6 figures, 1 table, published in Nature Communications

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• EXTraS discovery of an X-ray superflare from an L dwarf
• Detections of Multi-Periodic Oscillations during a Circular Ribbon Flare
• Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
• Statistical analysis of circular-ribbon flares
• Highly Energetic Electrons Accelerated in Strong Solar Flares as a Preferred Driver of Sunquakes
• Unveiling Spatiotemporal Properties of the Quasi-periodic Pulsations in the Balmer Continuum at 3600 Å in an X-class Solar White-light Flare
• High-resolution Observations of a C9.3 White-light Flare and Its Impact on the Solar Photosphere