- Why in news
- On 20 May 2026 the Ministry of Science & Technology reported a study by ARIES Nainital and IIT Delhi. It shows how Alfvénic waves can create spectral line asymmetries, a new way to detect hidden turbulence in the Sun's corona.
- What it is
- The coronal heating problem asks why the Sun's corona, its outer atmosphere, is at millions of degrees while the visible surface (photosphere) is only about 6,000 K. Alfvénic waves are magnetohydrodynamic waves that travel along magnetic field lines in plasma. They are a leading candidate for carrying energy upward and heating the corona.
- Who did the study
- ARIES Nainital, an autonomous institute of the Department of Science and Technology, worked with IIT Delhi. The researchers were Ambika Saxena and Prof. Vaibhav Pant.
- Mechanism
- Wave evolution creates fine-scale structure through phase mixing, which leads to turbulence.
- Why asymmetry appears
- The corona is optically thin, so emission from regions moving at different velocities overlaps along the line of sight. The line then shows alternating blue and red wing asymmetries.
- Size of the effect
- Simulated asymmetries reach about 20 percent of the line peak intensity, with apparent secondary velocities of 30 to 40 km per second.
- Observation prospect
- High-resolution facilities such as DKIST may soon allow the phenomenon to be observed.
Don’t confuse with Corona vs photosphere: The photosphere is the visible surface at about 6,000 K. The corona is the outer atmosphere, at over a million kelvin.
Don’t confuse with Alfvénic waves vs flows or jets: Earlier work read blueward asymmetries as upward flows or jets. This study shows transverse Alfvénic waves can also produce asymmetries.
Science and technology: 57 Prelims questions since 2013; most test the concept behind the news, not the news itself. In Mains, 12 news-triggered questions.
Why it matters
- Offers a new diagnostic to detect hidden turbulence, which may help explain coronal heating.
- Shows Indian institutions contributing to solar physics research.
Problems
- The results come from simulations. They are not yet confirmed by observation.
- Observing the effect needs very high spatial and spectral resolution.
Way forward
- Test the predicted asymmetries with high-resolution instruments such as DKIST.
- Link such diagnostics with data from solar missions to quantify wave heating.
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UPSC’s own questions that come close to this issue, from our Prelims and Mains banks.
No practice question for this one; the card may still help an answer. Why: Science concept questions are 17% of news-linked Prelims; this is a research finding with few testable facts.
Worth revising until Prelims 2027: most news questions come within two years of the event.