New Delhi | India's first space-based mission to observe the Sun, Aditya-L1, has observed "iron fluorescence" on the Sun during massive solar flares, according to a new study.
The iron fluorescence phenomenon occurs due to the eruption of a huge solar flare, which heats the Sun's upper atmosphere (the corona) to extreme temperatures, releasing massive bursts of high-energy X-rays, the ISRO said in a statement on Friday.
While most of these X-rays are emitted outward into space, a fraction travels downward, interacting with the Sun's cooler, denser surface layer called the photosphere, where they interact with abundant neutral iron atoms, which then emit their own characteristic X-ray glow or fluorescence.
Aditya-L1's Solar Low Energy X-ray Spectrometer (SoLEXS) has the capability to detect this phenomenon.
The study, published in the "Solar Physics" journal, revealed that the observed brightness of the iron fluorescence depends heavily on where the flare occurs on the Sun's disk.
"Flares occurring near the centre of the Sun's disk, as viewed by the observer, showed a strong fluorescence signal, while the signal was heavily suppressed for flares occurring near the Sun's edge," the Indian Space Research Organisation (ISRO) said.
The findings will now help researchers use the iron fluorescence as a potential diagnostic tool to probe the altitude of the coronal X-ray source high up in the solar atmosphere and study the unique viewing geometries of these explosive events.
