SUIT-ed and flared up

India"s maiden solar mission, Aditya-L1, has captured a powerful eruption of a solar flare in the near ultraviolet region of the Sun with its payload, the Solar Ultraviolet Imaging Telescope (SUIT). This was reported in a recent paper (bit.ly/flare-Aditya). It reveals how a solar flare transits the Sun"s photosphere and chromosphere — regions that were previously unobserved in this context. The discovery will enable scientists to track the flow of energy through the Sun"s atmosphere in real time.

"The goal was to understand how energy and matter move between the Sun"s layers and uncover the energetic processes behind these powerful solar events," says Durgesh Tripathi, a solar physicist at the Inter-University Centre for Astronomy and Astrophysics and the principal investigator of SUIT.

On February 22, 2024, sensors on board detected activity in a specific area of the solar disc. SUIT responded by focusing on the region and capturing the solar flare as it unfolded. Flares are typically observed in high-energy radiation, but SUIT captured detailed images of the flare as it blazed through the chromosphere and photosphere, which are visible in the ultraviolet range. This observation is akin to discovering a missing piece of information about the leaps of accelerated charged particles in the middle layers of the solar atmosphere, Tripathi explains.

"This is of fundamental importance to the field of solar physics given that much of the dynamic activity of our star originates in those layers, governed by magnetic fields that emerge through the Sun"s surface," says Dibyendu Nandi, a solar physicist at the Indian Institute of Science Education and Research Kolkata and a co-author of the study.

Once scientists comprehend this initiation process, they can better understand the broader implications of solar flares on space weather. The observations will also be critical in understanding the stellar atmosphere. The Aditya mission also carries instruments for observing hard and soft X-rays emitted during solar flares, enabling a comprehensive study from the near-ultraviolet to the hard X-ray spectrum. Researchers will get a full picture of the spectral energy distribution of a solar flare. Tripathi says the current findings are just the beginning, and a further analysis of the data will gradually yield more fundamental insights into solar flares.

"This study will provide new insights into how high-energy particles from the flare interact with the Sun"s lower atmosphere and how the chromospheric plasma responds," says Abhishek Kumar Srivastava, a solar physicist at the Indian Institute of Technology, Banaras Hindu University.