Scientists discover faster rotation in the Sun’s upper atmosphere
1. At a Glance
- Indian researchers found that the Sun's upper atmosphere (corona) rotates faster than its visible surface (photosphere), and rotation speed increases with height above the surface — a result that challenges classical physics expectations [S1].
- Findings will refine space weather models, relevant to satellite operations, communication, navigation, and power-grid resilience on Earth [S1].
- Relevant for UPSC as a science & technology current affair tying Indian solar research institutes (ARIES, USO, PRL) to global observational data (Japan) [S1].
- Part of India's growing indigenous solar physics ecosystem, alongside missions like Aditya-L1 [S1].
2. Why in the News
- Study published in Astronomy & Astrophysics Letters (2025); publicized via PIB/DST press release dated 30 July 2026 [S1].
- Findings show rotation velocity of the Sun's atmosphere increases with altitude, and decreases slightly during heightened sunspot activity, a previously poorly understood behaviour [S1].
3. Background & Evolution
- The Sun's differential rotation (equator rotates faster than poles) at the photosphere level has long been established; this study extends the analysis to the upper/coronal atmosphere [S1].
- Related prior DST-backed work: mapping of chromospheric differential rotation using 100 years of Kodaikanal Observatory data, and identification of "magnetic trees" revealing hidden flows in the solar upper atmosphere — both from DST-affiliated institutes, indicating a sustained Indian research programme on solar rotation dynamics [S1].
- Present study used the 2D image-correlation method, comparing solar images across separate days to compute rotational shifts/velocity [S1].
4. Core Static Facts
| Item | Detail |
|---|---|
| Nodal Ministry | Department of Science and Technology (DST), Ministry of Science & Technology [S1] |
| Lead institutes | ARIES (autonomous DST institute), Udaipur Solar Observatory (USO), Physical Research Laboratory (PRL), Ahmednagar College [S1] |
| Key researchers | Srinjana Routh, Vaibhav Pant (IIT Delhi), Anshu Kumari, Jaydeep Kandekar [S1] |
| Data source | Nobeyama Radioheliograph, Japan |
| Method | 2D image-correlation method (day-to-day image shift analysis) [S1] |
| Publication | Astronomy & Astrophysics Letters, 2025 [S1] |
| Core finding | Coronal/upper-atmosphere rotation > surface rotation; speed rises with height; speed dips slightly with higher sunspot activity [S1] |
5. Multi-Dimensional Analysis
Scientific / Technological - Uses radio-heliograph imaging (non-Indian instrument, Japan) combined with Indian institutional analysis — reflects international data-sharing in astronomy [S1]. - Builds on a body of DST-funded solar studies (Kodaikanal 100-year dataset, "magnetic trees" flow study) showing a coherent national research trajectory in solar physics [S1].
Economic / Strategic (Space Weather) - Better rotation models improve space weather forecasting, protecting satellites, GNSS/navigation, communications, and power grids from solar-storm-induced disruptions [S1].
Administrative - Demonstrates DST's role in funding autonomous research institutes (ARIES, PRL, USO) that collaborate with academic institutions (Ahmednagar College, IIT Delhi) [S1].
Historical - Extends decades-old solar differential rotation studies from the photosphere to previously less-charted atmospheric layers [S1].
6. Recent Developments (last 12-18 months)
- 30 July 2026: PIB/DST press release announcing the discovery of faster upper-atmosphere solar rotation [S1].
- Preceding related DST releases: "Magnetic Trees help researchers unearth hidden flow in the Sun's upper atmosphere" and "Astronomers map the differential rotation of the Sun's chromosphere using 100 years of Kodaikanal data" [S1].
7. Prelims Hooks
- The Sun's upper atmosphere rotates faster than its visible surface (photosphere) [S1].
- Rotation speed of the solar atmosphere increases with height above the surface [S1].
- Rotation speed decreases slightly during periods of intensified sunspot activity [S1].
- Study published in Astronomy & Astrophysics Letters, 2025 [S1].
- Data sourced from the Nobeyama Radioheliograph in Japan [S1].
- Method used: 2D image-correlation technique [S1].
- Nodal Indian institutes: ARIES, Udaipur Solar Observatory, Physical Research Laboratory, Ahmednagar College [S1].
- Nodal ministry: Department of Science and Technology (DST) [S1].
- ARIES is an autonomous institute under DST [S1].
- Findings aid space weather models affecting satellites, communication, navigation, and power infrastructure [S1].
- Related earlier DST study used 100 years of Kodaikanal Observatory data to map chromospheric differential rotation [S1].
- Another related DST study identified "magnetic trees" revealing hidden flow patterns in the Sun's upper atmosphere [S1].
8. Mains Relevance
- GS-III: Science and Technology — developments and their applications; achievements of Indians in science [S1].
- Possible question stems: 1. "Discuss the significance of recent Indian research on solar atmospheric rotation for space weather preparedness. (250 words)" 2. "Examine the role of autonomous institutes like ARIES and PRL in advancing India's astrophysical research capacity. (150 words)" 3. "How does understanding solar differential rotation contribute to protecting critical infrastructure from space weather hazards? (250 words)"
9. Related Topics to Study Next
- Aditya-L1 Mission (ISRO) — India's dedicated solar observation satellite, complements ground-based solar rotation studies.
- Space weather and its impact on satellites/power grids — practical stakes of solar atmosphere research.
- Kodaikanal Solar Observatory — source of century-long solar data used in related DST studies.
- Sunspot cycle and solar maximum/minimum — links to the sunspot-activity finding in this study.
- Differential rotation of the Sun — foundational astrophysics concept extended by this research.
- DST autonomous institutes (ARIES, PRL, USO) — administrative/institutional science governance angle.
- Coronal Mass Ejections (CMEs) and geomagnetic storms — downstream phenomena tied to solar atmospheric dynamics.
10. Common Errors / Trap Areas
- Confusing the nodal ministry: this is a DST initiative, not ISRO or MoES (Ministry of Earth Sciences) — though space-weather effects are also studied by ISRO's Aditya-L1 [S1].
- Mixing up photosphere (visible surface) vs corona/upper atmosphere — the surface rotates slower, not faster [S1].
- Assuming the observational data came from an Indian telescope — it was sourced from Japan's Nobeyama Radioheliograph [S1].
- Conflating this study with the separate "magnetic trees" or "Kodaikanal 100-year data" DST releases — they are related but distinct studies [S1].
- Misremembering the direction of the finding: rotation speed increases with height, not decreases [S1].
11. Sources
- [S1] Scientists discover faster rotation in the Sun's upper atmosphere — Department of Science & Technology (DST) — https://dst.gov.in/scientists-discover-faster-rotation-suns-upper-atmosphere — (tier: 1)