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Abstract We analyze high-resolution observations of an X-1.0 white-light flare, triggered by a filament eruption, on 2022 October 2. The full process of filament formation and subsequent eruption was captured in the Hαpassband by the Visible Imaging Spectrograph (VIS) on board the Goode Solar Telescope (GST) within its center field of view. White-light emissions appear in flare ribbons following the filament eruption and Hαribbon brightening. GST Broadband Filter Imager data show that the continuum intensity, as compared to the nearby quiet-Sun area, has increased by up to 20% in the photospheric TiO band around 7057 Å. The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory reported 10% contrast enhancement in the continuum near Fei6173 Å line. The separation motion of two white-light kernels is recorded by the high-cadence GST/TiO images and is well accompanied by the motion of the VIS Hαflare ribbon leading edge. One kernel, located in a 150 Gauss field within a granulation area, exhibited an average apparent motion speed of 55 km s−1, which is the highest average speed ever reported. The other kernel drifted at 9 km s−1in an 800 Gauss magnetic field area. Hard X-ray (HXR) emissions reaching up to 300 keV have been observed for this flare. The simultaneous occurrence of high-cadence HXR, microwave, and white-light emissions strongly suggests that the energetic particles from the flare directly contribute to the heating. The inverted HXR energy flux density corresponding to 10% TiO brightening is 2.07 ± 0.23 × 1011erg cm−2s−1during the flare peak.
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This content will become publicly available on July 28, 2026
High-resolution Observations of an X6.4 Solar Flare in the Mid-infrared
Abstract We present a unique observation of the X6.4-class flare SOL2024-02-22T22:34 using the Mid-InfraRed Imager (MIRI) at the Goode Solar Telescope. Three ribbon-like flare sources and one unidentified source were detected in MIRI’s two mid-infrared (mid-IR) bands at 5.2 and 8.2μm. The two stronger ribbons displayed maximum mid-IR enhancements of 21% and 18% above quiet-Sun levels and 10% in Helioseismic and Magnetic Imager (HMI) continuum intensity (Ic). The weak ribbon and the unidentified source had maximum mid-IR enhancements of 7% but showed HMI/Icdimmings, instead of excess emissions. Our result suggests that mid-IR emission forms in a higher layer during the flare and is more sensitive to flare heating than HMI/Icemission. The MIRI observations have high temporal resolution (2.6 s cadence in these observations) and show apparent source motions. One flare ribbon extends along weak vertical magnetic-field channels in the sunspot umbra, light bridge, and penumbra, with an approximately 30 s delay between HMI/Icand 8.2μm emissions. Meanwhile, the unidentified source moved at an apparent speed of 130 km s−1from a mixed-polarity area to one flare ribbon with a strong HMI/Icenhancement. We studied available hard X-ray/microwave imaging spectroscopy and used nonlinear force-free field extrapolation modeling to identify flare structures. The observational evidence strongly favors the chromospheric origin of the unidentified mid-IR source. Comparison with the X1.0 flare SOL2022-10-02T20:25 indicates that the total amount of high-energy electron (>60 keV) flux density is a key factor in determining the total brightening area and the maximum intensity enhancement in HMI/Icemissions.
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- PAR ID:
- 10618799
- Publisher / Repository:
- American Astronomical Society.
- Date Published:
- Journal Name:
- The Astrophysical Journal Letters
- Volume:
- 988
- Issue:
- 2
- ISSN:
- 2041-8205
- Page Range / eLocation ID:
- L56
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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