Scientists working with India’s first dedicated solar observatory, Aditya-L1, have reported a breakthrough in understanding the early warning signs of solar flares. The mission has detected small, short-lived brightening in the Sun’s atmosphere that appear hours before a major flare erupts.

These transient events cluster around the very location where the flare later occurs, offering a potential predictive marker for space weather forecasting.

The findings were published in the Monthly Notices of the Royal Astronomical Society (MNRAS) and draw upon simultaneous ultraviolet and X-ray observations from three payloads aboard Aditya-L1.

Solar flares are sudden bursts of electromagnetic radiation caused by the release of magnetic energy. Large flares can disrupt radio communication, interfere with navigation systems, damage satellites, and increase radiation hazards for astronauts and spacecraft. Understanding how these flares are triggered is critical for improving space weather forecasting and protecting modern technological infrastructure.

Aditya-L1, positioned at the Sun–Earth Lagrange Point 1 (L1), provides an uninterrupted view of solar activity across multiple wavelengths. The Solar Ultraviolet Imaging Telescope (SUIT) observes the Sun in eleven near-ultraviolet filters, revealing layers from the upper photosphere to the chromosphere. 

These wavelengths are largely inaccessible from Earth due to atmospheric absorption. Complementing SUIT are two X-ray instruments, the Solar Low Energy X-ray Spectrometer (SoLEXS) and the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS), which measure X-ray emissions produced by energetic processes in the solar corona. Together, these instruments allow scientists to study how activity in the lower solar atmosphere links to energy release in the corona during flare build-up.

Analysing several solar flare events in the Mg II h filter of SUIT, researchers identified numerous transient brightening events in active regions before major flares. Some of these showed corresponding X-ray signatures, confirming their association with magnetic energy release.

These pre-flare events clustered around the location of the subsequent flare, suggesting that repeated small-scale energy release progressively destabilises the magnetic field in an active region, eventually triggering a large flare.

Representative pre-flare transient events were observed in the Mg II h filter of SUIT on 1 November 2024. Red contours outlined the transient brightening identified in the pre-flare phase at three different times, demonstrating the systematic nature of these signals.

This study is one of the first to systematically investigate pre-flare activity using simultaneous ultraviolet imaging and X-ray observations from a single observatory.

The results provide valuable insights into the physical processes that trigger solar flares and move scientists closer to reliable flare forecasting. Such forecasting will contribute to better space weather prediction, helping protect satellites, astronauts, communication systems, and other critical technologies.

The research was led by the Manipal Centre for Natural Sciences (MCNS), Manipal Academy of Higher Education (MAHE), in collaboration with ISRO/DOS and other academic institutions.

The study highlights the growing scientific impact of India’s flagship solar mission, Aditya-L1, and reinforces India’s expanding role in global space science.

The mission’s ability to combine ultraviolet and X-ray data in real time represents a significant advancement in solar physics and space weather research.

ISRO