Astronomers using the Inouye Solar Telescope have captured the sharpest solar flare images ever taken, revealing delicate plasma loops as narrow as 21 kilometers. These ultra-fine structures, caught during an explosive X-class flare, provide the clearest evidence yet of the Sun’s hidden architecture and may represent the fundamental building blocks of flare activity.
The most detailed images ever taken of a solar flare at the H-alpha wavelength are giving scientists a new look at the Sun’s magnetic structures. Using the U.S. National Science Foundation’s Daniel K. Inouye Solar Telescope, researchers recorded remarkably fine strands of dark coronal loops during the fading stage of an X1.3-class flare on August 8, 2024. These loops measured an average width of 48.2 km, with some appearing as slim as 21 km.
Coronal loops are glowing arcs of plasma shaped by the Sun’s magnetic field lines. They often appear before solar flares, which occur when certain magnetic field lines twist and break, releasing bursts of energy. The Inouye telescope can highlight specific features of the Sun that remain invisible in other kinds of observations.
The high-resolution movie of the flare, captured by the Inouye Solar Telescope, has been sped up 100 times, revealing both bright ribbons and dark overlying coronal loops. The image is about 4 Earth diameters on each side.
“This is the first time the Inouye Solar Telescope has ever observed an X-class flare,” explains Cole Tamburri, lead author of the study. “These flares are among the most energetic events our star produces, and we were fortunate to catch this one under perfect observing conditions.”
The research team’s findings confirm theories on coronal loop scales, which have long suggested that they could be anywhere from 10 to 100 km in width. The observation of ultra-fine structures has opened the door to studying not just their size, but also their shapes and evolution.
The imagery itself is breathtaking, revealing dark, threadlike loops arching in a glowing arcade. This landmark moment in solar science marks a significant advance in understanding the Sun’s behavior and may improve our ability to predict space weather.
Reference: “Unveiling Unprecedented Fine Structure in Coronal Flare Loops with the DKIST” by Cole A. Tamburri, Maria D. Kazachenko, Gianna Cauzzi, Adam F. Kowalski, Ryan French, Rahul Yadav, Caroline L. Evans, Yuta Notsu, Marcel F. Corchado-Albelo, Kevin P. Reardon and Alexandra Tritschler, 25 August 2025, The Astrophysical Journal Letters.
DOI: 10.3847/2041-8213/adf95e
Source: https://scitechdaily.com/the-suns-hidden-threads-revealed-in-stunning-solar-flare-images