New Study Paves Way for Solving the Mysteriously High Temperature of the Solar Corona

📌 Summary:

• A new study offers a novel way to detect hidden turbulence in the Sun's outer atmosphere (the corona), helping address the long-standing mystery of why the corona is much hotter than the Sun's visible surface

• The study was conducted by ARIES, Nainital (an autonomous institute of the Department of Science and Technology) and IIT Delhi, and published in The Astrophysical Journal

• Researchers used advanced three-dimensional magnetohydrodynamic (MHD) simulations with forward modelling of propagating transverse (Alfvenic or kink) waves

• They found that transverse MHD waves alone can generate alternating blue and red spectral line asymmetries through phase mixing and wave-driven turbulence

• The simulated asymmetries reach up to about 20% of the line peak intensity, with apparent secondary velocities of 30-40 km/s

• The findings provide a new diagnostic tool; high-resolution facilities such as DKIST may soon enable observational confirmation

🎯 UPSC Relevance: GS3 — science and technology, space and solar physics research, and India's contribution to fundamental research.

📝 Prelims Facts:

• ARIES = Aryabhatta Research Institute of Observational Sciences, Nainital, an autonomous institute under the Department of Science and Technology (DST)

• The corona is the Sun's outermost atmosphere; the 'coronal heating problem' is why it is hotter than the photosphere

• MHD = magnetohydrodynamics; the waves studied are transverse Alfvenic or kink waves

• The study was published in The Astrophysical Journal

🔑 Key Term: Coronal Heating Problem — the unsolved puzzle of why the Sun's corona (millions of degrees) is far hotter than its visible surface (around 6,000 degrees Celsius).