Never-before-seen images show the Sun is teeming with tiny whirling vortices. Here's why it's a groundbreaking discovery

Scientists using the US National Science Foundation Daniel K. Inouye Solar Telescope made a major breakthrough in solar physics. They discovered Kelvin-Helmholtz Instability (KHI) – tiny swirling patterns like small whirlpools – on the surface of the Sun. It's said that the finding could help explain explosive solar activity and other solar phenomena.

The "groundbreaking" discovery was announced by the US National Science Foundation National Solar Observatory (NSF NSO) in a press release on Wednesday, August 5.

It said the new findings could "fundamentally change how we understand the physical mechanisms driving solar activity and its impacts on life on Earth."

An effect caused by fluid motion, Kelvin-Helmholtz Instability occurs when two fluids slide past each other at different velocities creating a “shear” at the interface—causing small disturbances to grow into striking, wave-like or spiraling, vortices that look like breaking ocean waves.

What is the ‘groundbreaking’ discovery?

According to the press release, a team of international researchers from the NSO, the NSF NCAR High Altitude Observatory (HAO), and the German Max Planck Institut für Sonnensystemforschung (MPS) discovered Kelvin-Helmholtz instability (KHI) "in the form of small, swirling, whirlpool-like patterns on the surface of the sun (the photosphere)."

The research, published in the journal Nature, is based on data collected with the world’s largest solar telescope, the NSF Daniel K. Inouye Solar Telescope, built and operated by NSO on the island of Maui, HI.

The time-lapse video and images released on Wednesday revealed a solar landscape unlike any that had been seen before, uncovering small-scale and dynamic swirls everywhere at the edges of magnetic areas.

"This allowed for the unambiguous identification of KHI in the photosphere, providing the first experimental confirmation of a phenomenon that has long been predicted by theory but could only be revealed by the Inouye Solar Telescope’s high spatial resolution," the statement said.

The NSO also released the highest-resolution image of the Sun’s surface (photosphere) "ever captured, taken at 416 nm by the Inouye Solar Telescope." It reveals deformed boundaries of magnetic elements and ultra-fine scale stripes, both associated with Kelvin-Helmholtz instability.

“It is very exciting to see that the highest-resolution observations of the solar photosphere revealed a new dynamical regime in the form of KH vortices at the edges of magnetic field concentrations. These observations also provide the highest resolution validation of solar magnetohydrodynamic simulations to date, and the agreement in physical details is impressive," said Dr. Matthias Rempel, Senior Scientist at the High Altitude Observatory.

The team’s advanced analyses of the Inouye observations and the computer simulations, combined with their agreement with analytical theory, led to the conclusion that the swirling vortices, and the fast-moving, finest-scale dark stripes (“striations”), found in both the observations and simulations are, without a doubt, produced by Kelvin-Helmholtz instability (KHI).

“We believe that the discovery of Kelvin-Helmholtz instability in the solar photosphere, backed up by analysis of numerical simulations, is a major step forward in our understanding of the dynamics and evolution of solar and stellar plasma, and will serve as a basis for future discoveries," said Dr David Boboltz, Deputy Director at the National Solar Observatory.

Why is the Sun so hot?

According to the US National Science Foundation National Solar Observatory, researchers suggest that Kelvin-Helmholtz instability might be a key reason why the Sun’s outer atmosphere gets so hot, and why magnetic energy builds up and moves around on the Sun.

“Magnetic energy fuels solar flares and eruptions—the kind of solar activity that can send bursts of energy toward Earth and affect satellites, power grids, and other technology,” the press release stated.

Dr. Thomas Rimmele, Chief Technologist at the National Solar Observatory, said Kelvin-Helmholtz instability is likely a mechanism that contributes to the heating of the outer atmosphere and is part of the solution of the longstanding enigma of why stars have a million degrees Kelvin hot corona.

What's next?

Scientists are now moving towards the next phase of analysis, which includes using computer programs that can automatically spot and study these swirling patterns — aided by the high resolution data from the Inouye Solar Telescope.

This next phase of research will help in two main ways: it’ll show scientists more about how much energy these KHIs can carry up into the Sun’s higher atmosphere, where it helps heat things up, and it’ll also help scientists figure out just how much they affect the way magnetic fields spread out in the lower parts of the Sun’s atmosphere.

“To understand the dynamic space weather that affects Earth, we have to see the small-scale processes driving it. For decades, seeing these vortices at such tiny scales remained elusive. By pairing a massive four-meter mirror with state-of-the-art optics and instruments, the NSF Inouye Solar Telescope delivers the resolving power needed to reveal these ultrafine details for the first time, enabling discoveries that were once beyond our reach," said Dr. Jacqueline Keane, NSF Program Director for the National Solar Observatory.