Aditya-L1 completes one year of Solar observations, offers new insights into the Sun's activity

India's Aditya-L1 solar mission has completed a year of scientific observations with its Solar Ultraviolet Imaging Telescope (SUIT), giving researchers valuable insights into the Sun's lower atmosphere and the activity behind solar flares and other disturbances. A research paper detailing SUIT's first year in operation describes how scientists calibrated, maintained and operated the instrument while recording important solar features. The findings add to efforts to understand how activity in the Sun's atmosphere develops and how it can affect Earth's space environment. The study, titled Unravelling the Secrets of the Lower Solar Atmosphere: One Year of Operation of the Solar Ultraviolet Imaging Telescope (SUIT) on board Aditya-L1, was led by Rahul Gopalakrishnan and a team of researchers.

It has been accepted for publication in the Journal of Astrophysics and Astronomy. Aditya-L1: India's first dedicated Solar observatory Launched by the Indian Space Research Organisation (ISRO) on September 2, 2023, Aditya-L1 is India's first dedicated space-based solar observatory. The spacecraft entered its designated halo orbit around the Sun-Earth Lagrange Point 1 (L1) on January 6, 2024, at a distance of about 1.5 million kilometres from Earth. The L1 point offers the spacecraft a largely uninterrupted view of the Sun. Unlike observatories affected by Earth's shadow and regular eclipses, Aditya-L1 can monitor solar activity continuously, making it easier for scientists to track changes in the Sun.

The mission is designed to investigate several key questions, including how the Sun's outer atmosphere becomes extremely hot, how solar flares and coronal mass ejections originate, and how these events influence space weather. What has Aditya-L1's SUIT instrument observed? SUIT is one of the seven scientific instruments aboard Aditya-L1. It captures images of the Sun in near-ultraviolet light, covering wavelengths between 200 and 400 nanometres. The instrument was switched on November 20, 2023, and recorded its first scientific images on December 6, 2023, while the spacecraft was still travelling towards the L1 point.

Its ultraviolet observations allow scientists to study features in two important layers of the Sun's atmosphere: the photosphere and the chromosphere. These regions provide clues about how solar activity begins and develops. The research paper documents SUIT's performance during its first year, including its calibration, maintenance routines, operating procedures and observations. It also highlights notable solar features and events captured during this period. Why studying the Sun's lower atmosphere matters The Sun is an active star, with eruptions and disturbances that can send energy and charged particles into space.

Understanding how these events begin in its lower atmosphere can help researchers trace their development and assess their possible effects. Solar flares and coronal mass ejections can influence the space environment around Earth. Strong solar activity may disrupt satellite operations, radio communications and navigation systems. In extreme cases, geomagnetic disturbances can also affect power infrastructure. By observing the Sun in ultraviolet wavelengths, SUIT helps scientists investigate the processes that connect activity in the lower atmosphere with larger solar events. Such research is important for improving our understanding of space weather and its potential impact on technology.

As Aditya-L1 continues its observations, scientists will have more data to investigate solar activity and improve their understanding of space weather.