It took astronomers a little over a year to analyze the sharpest-ever images of a solar flare. But they’re finally done, and the results are illuminating—literally and figuratively.

Last year, NSF’s Daniel K. Inouye Solar Telescope captured a high-resolution image of a solar flare crossed with dark strands of coronal loops. Further analysis revealed that the solar flare was an X-class flare—the most powerful class—in a decay phase. The coronal loop strands averaged around 30 miles (48 kilometers) in width, with a minimum thickness of 13 miles (21 km), which would make them the smallest coronal loops ever seen. A detailed account of the imaging and analysis was published in The Astrophysical Journal Letters on August 25, 2025.

“These flares are among the most energetic events our st

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