数学家追日十九次：算法与相机揭开日冕之谜

The sun hangs low over the plains of Castile and León, in the north-central region of Spain. But from a slope of the mountain Pico Trigaza , it appears that a few puffy white clouds have started to block the sun. That’s vexing. A group of researchers, some wearing cardboard eclipse glasses, is clustered around sets of portable telescopes and cameras connected to laptops. All this gear is scattered on tabletops perched on the mountainside. On the computer screens, the sun’s disk looks like a deep orange crescent that is slowly waning. That’s because the moon began to crawl across it about half an hour ago. In 25 minutes, it will obscure the sun completely, producing an eerie and wondrous phenomenon—a total solar eclipse. In the late-summer, late-afternoon heat, the researchers watch anxiously as those fluffy clouds linger around the sun. From an abandoned hut on the slope a few meters above, where the researchers have set up camp, one of the grad students emerges and nods toward the cloud formation. “Do you think it will dissolve?” he blurts out. “It will.” Miloslav Druckmüller glances calmly at his group of doctoral candidates, now making final checks of the equipment in preparation for totality. Here in Spain, on this 12th day of August, Druckmüller is getting ready for his 19th solar eclipse. He knows from long experience that weather can turn quickly when the moon’s shadow suddenly pushes the temperature down. Plus, there’s no sense in riling up the grad students any more than they already are. Miloslav Druckmüller led the design and construction of a unique optical instrument that incorporates eight astrocameras. Each is equipped with a spectral filter for sensing and recording specific emission spectra from the solar corona. Each of those spectra, in turn, is associated with a particular ionic species of iron atoms. Because the temperature needed to ionize iron varies depending on the ionic species, analyzing the locations and relative abundance of these ionic species offers valuable insights into the distribution of heat in the corona. Václav ?irok? During totality, the moon blocks the overwhelming glare of the solar disk, revealing delicate structures in the sun’s outer atmosphere, the corona. Using custom-built telescope systems and image-processing techniques that Druckmüller has spent decades developing, the researchers aim to gain insights into the processes in this enigmatic region that is otherwise hard to study . In addition to imaging the visible coronal light, the team will try to track the dispersal of superhot ions of iron into interplanetary space, which could give rare insights into the pattern of heat emanating from the corona. And they’ll have 107 seconds to do all that. A Mathematician’s Path to Solar Eclipse Photography Druckmüller is a professor of mathematics and image processing at the Brno University of Technology in the Czech Republic and a leading figure in the Solar Wind Sherpas , an international team that studies the sun’s corona during total eclipses. In the solar eclipse world, he is nothing short of a legend, albeit a reluctant one. An image from Miloslav Druckmüller’s first solar-eclipse expedition, to Hungary, vividly shows Baily’s Beads. These elongated white lights along a piece of the left edge of the blacked-out solar disk are caused by beams of sunlight shining through gaps in the irregular lunar surface during the eclipse. The pink shapes are solar prominences, which are jets of plasma extending out into space and held in place by the sun’s intense magnetic field. Miloslav Druckmüller He photographed his first solar eclipse in 1999, in what he thought would be a one-off lark. During that eclipse, the moon’s deep shadow missed Druckmüller’s native Czechia by just a few tens of kilometers, so he chased it to Hungary with a 30-year-old Soviet MTO 1,000-millimeter lens . All he remembers from that day is the rush of adrenaline he felt while trying to find the sun in the sky with the lens’s minuscule field of view and keep it in focus for the two minutes of the eclipse. He insists that he has never enjoyed any of the eclipses he has photographed. “In fact, I have never properly seen any of those eclipses. You are just watching the screens, making sure that it’s all doing what it’s supposed to do. There are so many things that can go wrong and you can’t redo it.” A composite sequence of photographs shows the 12 August 2026 solar eclipse as seen from a slope of the mountain Pico Trigaza in Spain. Václav ?irok? and Miloslav Druckmüller Despite Druckmüller’s outward tranquility on this Spanish hillside, the stakes are high. Just 45 minutes ago, his group heard from their colleagues in Iceland, where viewing conditions had promised to be better than in Spain. But a vast low-pressure system had clouded the entire sky, leaving all three Iceland teams without a view. What Solar Eclipses Reveal About the Corona The corona has been a mystery for centuries. Though dimmer—by a fac