The Daniel K. Inouye Solar Telescope in Hawaii has produced the highest spatial resolution images of the solar surface ever acquired, resolving features smaller than 20 kilometres across. The observations were made in a magnetically active region near a sunspot and published in Nature.
Previous images from the telescope, operated by the US National Solar Observatory, showed granular structures roughly the size of France with details as small as 30 kilometres. The new data push to the instrument's diffraction limit.
In the latest images, researchers identified small whirlpool-like structures as signatures of Kelvin-Helmholtz instabilities. These instabilities form when fast-moving plasma slides past slower-moving fluid, creating shear that generates spiralling vortices.
Kelvin-Helmholtz instabilities have been observed in Earth's oceans, lakes, and cloud formations, as well as in the atmospheres of Jupiter and Saturn, but had not been confirmed on the sun until now.
The vortices are considered a key mechanism for braiding magnetic field lines, which store energy that is released in solar flares, jets, and coronal mass ejections. These explosive events can disrupt power grids, satellites, and communications on Earth.
The energy cascade from these instabilities may dissipate as heat in the corona, potentially solving the decades-old mystery of why the sun's outer atmosphere reaches millions of degrees while the surface remains around 6,000°C.
Dr David Kuridze, an astronomer on the team, said the instability could explain how energy cascades to smaller scales and dissipates as heat, a process that may also occur in similar stars.
Dr Friedrich Wöger, a senior scientist at the National Solar Observatory, confirmed these are the highest-resolution solar surface images ever obtained.
Unprecedented images may explain one of greatest mysteries of the sun
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