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A new study by Indian scientists could help explain one of the biggest mysteries in solar science, why the Sun’s outer atmosphere, known as the corona, is far hotter than its visible surface.

Researchers from Aryabhatta Research Institute of Observational Sciences and Indian Institute of Technology Delhi have identified a new way to detect hidden turbulence inside the solar corona. The findings were published in The Astrophysical Journal.

The Sun’s corona can reach temperatures of more than one million degrees Celsius. In comparison, the Sun’s visible surface remains much cooler at nearly 5,500 degrees Celsius. Scientists have studied this temperature gap for decades.

Waves Inside The Sun’s Atmosphere Show New Clues

The research focused on magnetic waves moving through the corona. These waves, known as magnetohydrodynamic or MHD waves, travel along magnetic structures in the Sun’s atmosphere. They cause plasma to move sideways as the waves travel outward.

Using advanced three-dimensional simulations, researchers studied how these waves interact with uneven plasma structures in the corona. The team found that the waves create turbulence and fine-scale plasma motions over time.

As these motions overlap along the observer’s line of sight, they change the shape of light signatures known as spectral lines. Scientists observed alternating red and blue asymmetries in these lines, showing plasma moving at different speeds.