Solar Telescope Reveals Widespread Twisting Waves in Sun’s Corona

Breakthrough Solar Observations

Researchers using the National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST) have identified small-scale torsional waves throughout the Sun’s corona, according to a new study published in Nature Astronomy. The findings, obtained during the telescope’s commissioning phase on October 30, 2023, represent a significant advancement in understanding wave behavior in the Sun’s outermost atmosphere.

Breakthrough Solar Observations
Unveiling Hidden Solar Dynamics
Wave Characteristics and Significance
Scientific Implications

Sources indicate the 4-meter aperture telescope, equipped with the Cryogenic Near-infrared Spectropolarimeter (Cryo-NIRSP), provided unprecedented resolution to examine these previously undetectable phenomena. The observations focused on iron XIII emission lines at 1,074.7 nanometers from a fixed position approximately 0.1 solar radii above the Sun’s surface., according to expert analysis

Unveiling Hidden Solar Dynamics

Analysts suggest the research team employed sophisticated techniques to separate different types of wave motions within the coronal structures. According to reports, the data revealed both kink waves, which cause swaying motions of magnetic flux tubes, and the newly identified torsional Alfvén waves, which create twisting motions around the tube axis.

The study states that distinguishing between these wave types required careful analysis of Doppler velocity signals. Researchers reportedly developed methods to isolate the torsional component by removing the contribution from kink motions, revealing characteristic anti-phase velocity patterns on opposite sides of the magnetic flux tubes.

Wave Characteristics and Significance

The torsional waves display a range of timescales but appear to be broadband and stochastic rather than strictly periodic, according to the analysis. The report indicates these fluctuations typically show only two to three consistent cycles before changing character, similar to patterns previously observed in kink waves and solar wind fluctuations.

Sources indicate the mean velocity amplitude for the torsional Alfvén waves measures approximately 0.321 km/s before correction for line-of-sight integration effects. After accounting for these observational limitations, analysts suggest the true wave amplitudes likely reach about 19.5 km/s, consistent with values previously reported for chromospheric spicules.

Scientific Implications

The discovery has significant implications for understanding coronal heating and solar wind acceleration, according to researchers. The widespread presence of these waves throughout both open-field regions and quiet-Sun loops suggests they may contribute substantially to energy transport in the solar atmosphere.

Analysts suggest the simultaneous presence of both kink and torsional waves indicates a complex wave environment where multiple wave modes can coexist and potentially interact. The study states that both wave types appear to be driven by photospheric convective motions, though through different flow patterns operating at various spatial scales.

Researchers caution that some aspects of the wave behavior require further investigation, particularly instances where torsional signals appear to extend beyond individual flux tubes. The report indicates future observations with different instrumental configurations may help resolve remaining questions about wave propagation and energy transfer mechanisms.