Astronomers using the Daniel K. Inouye Solar Telescope in Maui, Hawaii, have captured the highest-resolution images yet of the Sun’s visible surface, revealing bands and swirling vortices smaller than 20 kilometers across near a sunspot.
The structures appear to be signatures of Kelvin–Helmholtz instabilities, which form when fast-moving plasma slides past slower plasma. Scientists say the process could help explain how the Sun’s magnetic fields become twisted and how energy may be transferred upward to heat the corona, its outer atmosphere, to millions of degrees.
At a glance:
- The observations were made with the Inouye Solar Telescope near the summit of Haleakalā on Maui.
- The images resolve features smaller than 20 kilometers, compared with about 30 kilometers in earlier Inouye observations.
- The newly identified structures resemble Kelvin–Helmholtz instabilities seen in fluids on Earth and in planetary atmospheres.
- The findings were published in Nature on August 5, 2026.
What the telescope revealed
The team examined a magnetically active region close to a sunspot. The images showed golden bands, distorted boundaries and whirlpool-like forms at the edge of magnetic structures, giving researchers a view of the photosphere at the limit of the telescope’s capability.
Friedrich Wöger, a senior scientist at the National Solar Observatory, described the observations as the highest spatial-resolution images of the solar surface ever acquired. Earlier Inouye images showed granules roughly the size of France and resolved details down to about 30 kilometers; the new observations reveal structures below 20 kilometers.
Why the vortices matter
Kelvin–Helmholtz instabilities develop where two fluids or plasmas move past one another at different speeds. The resulting shear can produce ripples that grow into spiraling vortices, similar to breaking waves on water or patterns in clouds.
Researchers have observed the phenomenon in terrestrial fluids and in the atmospheres of Jupiter and Saturn, but had not previously confirmed it directly on the Sun’s visible surface. The team identified the solar features as likely Kelvin–Helmholtz signatures because of their shape and their location along moving magnetic boundaries.
A possible link to solar storms and coronal heating
Solar flares, jets and coronal mass ejections are powered by changing magnetic fields. Scientists understand that magnetic field lines can become twisted and braided before suddenly releasing stored energy, but the small-scale motions that initiate this process remain uncertain.
The newly observed vortices provide a possible mechanism. As plasma shear cascades into smaller scales, energy may be dissipated as heat and may also help braid magnetic field lines. That could connect activity at the Sun’s surface with the corona’s extreme temperature, although further observations and modeling are needed to establish how much energy the process supplies.
Why it matters on Earth
Major solar eruptions can disturb infrastructure in space and on Earth, including satellites, GPS systems, communications networks and power grids. Better understanding of how magnetic energy builds and escapes could improve scientists’ ability to interpret and eventually forecast space-weather events.
David Kuridze, an astronomer on the research team, said the instability may help address one of the longstanding questions in solar physics: why the corona is millions of degrees hotter than the Sun’s surface, which is about 6,000 degrees Celsius. The new images offer evidence for a possible piece of that explanation, not a completed solution.
Questions readers ask
What is a Kelvin–Helmholtz instability?
It is a fluid or plasma instability created when adjacent layers move at different speeds. The velocity difference produces shear, ripples and eventually swirling vortices.
Did the study prove that these vortices heat the corona?
No. The observations identify a plausible process that could transfer and dissipate energy, but scientists still need additional observations and models to determine its contribution to coronal heating.
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