深空视界
深空视界
The smallest magnetic loops ever seen in the sun's corona — imaged for the first time by the National Science Foundation's Daniel F. Inouye Solar Telescope — could be the bottom floor of the machinery that powers the ferocious flares that routinely blast out from our star.
"It's a landmark moment in solar science," said Cole Tamburri of the University of Colorado, Boulder, in a . "We're finally seeing the at the scales it works on.""
Basically, are produced when magnetic field lines that loop through the sun's outer atmosphere, the , grow taut and snap, releasing energy before reconnecting once again. This has been known for some time, but the details involved in magnetic reconnection and solar flares, however, still require some working out. One big question has been: How small can these coronal loops go, and what role could these miniature loops play in powering solar flares??
The (DKIST), operated by the National Science Foundation's (NSF) National Solar Observatory, has now imaged hundreds of coronal loop strands that are just 29.95 miles (48.2 kilometers) wide on average, and some could be as thin as 13 miles (21 kilometers). These are right on the limit of the DKIST's resolution, which is itself more than 2.5 times sharper than the next best solar telescope..
"Before Inouye, we could only imagine what this scale looked like," said Tamburri. "Now we can see it directly."
The forest of small loops was seen in hydrogen-alpha light by DKIST's Visible Broadband Imager in the aftermath of an X-class flare — the most powerful category of flare that the sun can unleash — seen on Aug. 8, 2024.
"This is the first time the Inouye Solar Telescope has ever observed an X-class flare," said Tamburri. "These flares are among the most energetic events our star produces, and we were fortunate to catch this one under perfect observing conditions."