Aditya-L1 Detects Iron Fluorescence on the Sun, Marking Major Scientific Breakthrough

India's pioneering solar mission, Aditya-L1 , has achieved another scientific milestone by detecting iron fluorescence on the Sun during powerful solar flares, offering researchers a new way to study the Sun's atmosphere and the origins of high-energy solar activity.

The Indian Space Research Organisation (ISRO) announced on Friday that the observation was made using Aditya-L1's Solar Low Energy X-ray Spectrometer (SoLEXS) . The findings, published in the journal Solar Physics , mark the first time the mission has recorded this phenomenon, which occurs when intense X-rays produced by massive solar flares interact with the Sun's surface.

During a large solar flare, the Sun's outer atmosphere, or corona, is heated to extremely high temperatures, generating powerful bursts of X-rays. While most of these X-rays escape into space, some travel downward and strike the cooler photosphere , where abundant neutral iron atoms absorb the energy and emit a characteristic X-ray glow known as iron fluorescence .

According to the study, the strength of this fluorescence depends on the flare's position on the Sun. Flares occurring near the centre of the Sun's visible disk produced a much stronger fluorescence signal, while those near the edge of the Sun showed significantly weaker emissions due to differences in viewing geometry.

Scientists say the discovery is significant because iron fluorescence can serve as a diagnostic tool for determining the altitude of coronal X-ray sources during solar flares. This will help researchers better understand the structure of the Sun's atmosphere, the mechanisms behind explosive solar events, and the geometry of high-energy emissions.

Launched as India's first dedicated space-based mission to study the Sun , Aditya-L1 continues to provide valuable insights into solar activity, strengthening the country's contribution to global solar physics research and improving scientific understanding of phenomena that can influence space weather and satellite operations.