New study captures Sun’s early warning signs before solar flares

Science & Technology · 31 August 2026 · Based on The Hindu (original report)

2-minute summary

A collaborative study by Indian scientists, including researchers from ISRO and the Manipal Academy of Higher Education, has identified early warning signs of solar flares using data from India's Aditya-L1 mission. By analyzing simultaneous observations from three onboard payloads—the Solar Ultraviolet Imaging Telescope (SUIT), the Solar Low Energy X-ray Spectrometer (SoLEXS), and the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS)—the team detected small, short-lived brightening 'transient events' in the Sun's atmosphere hours before major flares occur. These transient events cluster around the future flare site, indicating small-scale magnetic energy releases that progressively destabilize the active region's magnetic field. This discovery provides critical insights into the physical triggers of solar flares, bringing scientists closer to reliable space weather forecasting that can protect satellites, communication networks, and power grids.

Why it's in the news

A new study using simultaneous ultraviolet and X-ray observations from three payloads onboard India's Aditya-L1 mission has successfully captured pre-flare transient events, providing a breakthrough in predicting major solar flares.

Background and context

Solar flares are sudden, intense explosions of radiation on the Sun caused by the release of magnetic energy. These events can trigger geomagnetic storms on Earth, disrupting high-frequency radio communications, GPS navigation, satellite electronics, and power grids, while posing severe radiation risks to astronauts. To study these phenomena, ISRO launched Aditya-L1 in September 2023, placing it in a halo orbit around the Lagrangian Point 1 (L1), approximately 1.5 million kilometers from Earth. This strategic position allows continuous, unobstructed observation of the Sun. Ground-based solar observation is limited because Earth's atmosphere absorbs ultraviolet radiation. Space-based instruments like those on Aditya-L1 are essential to capture these high-energy processes across ultraviolet and X-ray spectrums, enabling scientists to study the solar atmosphere from the photosphere to the corona.

Government schemes

• Aditya-L1 Mission — India's first dedicated scientific mission to study the Sun, providing the multi-wavelength data (SUIT, SoLEXS, HEL1OS) that enabled this scientific breakthrough.

Previous UPSC questions on this theme

• Prelims GS-1 2016 — With reference to 'Astrosat', the astronomical observatory launched by India, which of the following statements is/are correct? 1. Other than USA and Russia, India is the only country to have launched a similar observatory into space. 2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth. (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

Mains practice: Discuss the scientific and technological significance of India's Aditya-L1 mission. How do its recent findings on pre-flare transient events contribute to global space weather forecasting and the protection of critical space assets?

Aditya-L1, India's first dedicated space-based solar observatory, is positioned in a halo orbit around the Lagrangian Point 1 (L1). A recent collaborative study using its payloads has identified pre-flare 'transient events'—small, short-lived ultraviolet and X-ray brightenings—that serve as early warning signs hours before major solar flares erupt.

Scientific and Technological Significance of Aditya-L1:

• Continuous Observation: Positioned at L1, approximately 1.5 million km from Earth, it enjoys an unobstructed view of the Sun without any occultation or eclipses.

• Overcoming Atmospheric Barriers: Payloads like the Solar Ultraviolet Imaging Telescope (SUIT) observe the Sun in Near-Ultraviolet (NUV) wavelengths, which are otherwise absorbed by Earth's ozone layer and atmosphere.

• Multi-Wavelength Synergy: Simultaneous observations by SUIT (UV) and X-ray spectrometers (SoLEXS and HEL1OS) allow scientists to link magnetic activities in the lower solar atmosphere (photosphere/chromosphere) to energy releases in the outer corona.

Contributions of Recent Findings to Space Weather and Asset Protection:

• Early Warning & Forecasting: Detecting localized, small-scale magnetic energy releases (transient events) that progressively destabilize solar magnetic fields allows for reliable forecasting of major solar flares.

• Safeguarding Space Infrastructure: Advanced warnings help satellite operators temporarily put sensitive electronics into 'safe mode' to prevent damage from solar energetic particles.

• Protecting Communication and Navigation: Solar flares trigger geomagnetic storms that disrupt high-frequency radio communications, GPS, and power grids. Early forecasting mitigates economic and operational disruptions.

• Astronaut Safety: It provides crucial lead time to protect astronauts in space stations from lethal radiation exposure.

Conclusion: The findings from Aditya-L1 highlight India's growing capability in deep-space scientific research. Transitioning from basic space exploration to predictive space weather science positions ISRO as a key contributor to global planetary defense and space asset security.

Prelims practice questions

Q1. With reference to the Aditya-L1 mission, consider the following pairs of payloads and their scientific objectives: 1. SUIT: Observing the solar atmosphere in near-ultraviolet wavelengths. 2. SoLEXS: Measuring high-energy X-ray emissions from the solar corona. 3. HEL1OS: Measuring low-energy X-ray emissions from the solar corona. Which of the pairs given above is/are correctly matched?

1. 1 only
2. 1 and 2 only
3. 2 and 3 only
4. 1, 2 and 3

Answer: A. According to ISRO, the Solar Ultraviolet Imaging Telescope (SUIT) observes the Sun in near-ultraviolet (NUV) wavelengths. The Solar Low Energy X-ray Spectrometer (SoLEXS) measures low-energy X-rays, while the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) measures high-energy X-rays. Therefore, pairs 2 and 3 are incorrectly interchanged, and only pair 1 is correct.

Q2. Why are Near-Ultraviolet (NUV) observations of solar phenomena primarily conducted using space-based telescopes rather than ground-based observatories?

1. Ground-based telescopes suffer from thermal noise that mimics UV signatures.
2. Earth's magnetic field deflects ultraviolet photons away from the surface.
3. The Sun's UV emissions are only directed towards the Lagrangian points.
4. The Earth's atmosphere absorbs most of the ultraviolet radiation.

Answer: D. As highlighted by ISRO, near-ultraviolet (NUV) wavelengths are largely inaccessible from the ground because Earth's atmosphere (specifically the ozone layer and other gases) absorbs most ultraviolet radiation. Hence, space-based instruments like SUIT on Aditya-L1 are required.

Q3. A recent study using Aditya-L1 data suggested that major solar flares are preceded by which of the following phenomena?

1. Repeated small-scale energy releases that progressively destabilize the magnetic field
2. A temporary reversal of the Sun's global magnetic poles
3. The complete disappearance of sunspots in the active region
4. A sudden cooling of the solar corona's outer edge

Answer: A. The collaborative study found that small, short-lived brightening 'transient events' (representing small-scale magnetic energy releases) cluster around the future flare site. These repeated small-scale energy releases progressively destabilize the magnetic field in an active region, eventually triggering a large solar flare.

Revision flashcards

• Which payload on Aditya-L1 is designed to observe the Sun in near-ultraviolet (NUV) wavelengths? The Solar Ultraviolet Imaging Telescope (SUIT).
• Name the two X-ray spectrometers onboard Aditya-L1 that measure solar corona emissions. Solar Low Energy X-ray Spectrometer (SoLEXS) and High Energy L1 Orbiting X-ray Spectrometer (HEL1OS).
• Why can't Near-Ultraviolet (NUV) observations of the Sun be effectively done from ground-based observatories? Because Earth's atmosphere absorbs most ultraviolet radiation, making NUV wavelengths largely inaccessible from the ground.
• What physical mechanism did the Aditya-L1 study identify as the precursor to major solar flares? Repeated, small-scale energy releases (transient brightenings) that progressively destabilize the magnetic field in an active region.
• Where is the Aditya-L1 spacecraft positioned, and what is the main advantage of this location? At the Lagrangian Point 1 (L1), about 1.5 million km from Earth. It provides a continuous, unobstructed view of the Sun without eclipses or occultation.