AI reads 100 years of Kodaikanal hand-drawn suncharts to track bright solar regions
Researchers led by ARIES used machine learning on hand-drawn suncharts of the Kodaikanal Solar Observatory to trace magnetically active solar plages from 1916 to 2007, the Ministry of Science and Technology said on 1 July 2026.
Summary
Researchers led by Dibya Kirti Mishra of the Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute of the Department of Science and Technology, used artificial intelligence to trace the shift of magnetically active patches (plages) on the Sun from 1916 to 2007, covering Solar Cycles 15 to 23, the Ministry of Science and Technology said on 1 July 2026. The team applied a U-Net-based machine learning model to the hand-drawn daily suncharts of the Kodaikanal Solar Observatory (KoSO), which run from 1904 to 2022, and produced a time-latitude 'butterfly' map of plage area. Collaborators included IIST Thiruvananthapuram, the Southwest Research Institute in Boulder, USA, and the Indian Institute of Astrophysics, Bangalore.
Key facts
- Lead institute
- ARIES (autonomous institute of DST); lead researcher Dibya Kirti Mishra
- Data
- Kodaikanal Solar Observatory hand-drawn suncharts, 1904-2022
- Period traced
- 1916-2007 (Solar Cycles 15-23)
- Method
- U-Net-based machine learning detection of plages
- Collaborators
- IIST, SwRI (USA), IIA Bangalore
Practice MCQs 2 questions
The 2026 study that used AI on 100 years of Kodaikanal Solar Observatory suncharts was led by researchers from which institute?
Show answer
Correct answer: B — Aryabhatta Research Institute of Observational Sciences
The study was led by Dibya Kirti Mishra of ARIES, an autonomous institute under DST, with collaborators including IIA Bangalore.
In the AI study of Kodaikanal suncharts (July 2026), the shift of magnetically active solar patches (plages) was traced over which period?
Show answer
Correct answer: D — 1916 to 2007
The plages were traced from 1916 to 2007 (Solar Cycles 15-23); the KoSO suncharts themselves span 1904 to 2022.