Researchers used artificial intelligence to analyse more than a century of hand-drawn solar observations from the Kodaikanal Solar Observatory (KoSO) in Tamil Nadu. The study used digitised solar charts from 1904 to 2022 to create a long, continuous record of solar magnetic activity.
🔭 Kodaikanal Solar Observatory (KoSO)
The Kodaikanal Solar Observatory, also called KoSO, is a solar observatory in Tamil Nadu known for its long-running solar records. Its hand-drawn “suncharts” document daily solar observations and form a valuable historical archive used in solar physics.
🤖 AI Method & Solar Data
The study applied a U-Net-based supervised machine learning model to digitised suncharts. The model detected and mapped plages — bright, magnetically active regions on the Sun — across observations from 1916 to 2007, covering nine full solar cycles.
- Used a U-Net convolutional neural network for image segmentation.
- Detected and mapped plages (bright magnetic regions).
- Covered nine full solar cycles (1916–2007).
- Generated a time-latitude butterfly diagram of solar activity.
🏛️ Institutions & Publication
The research was led by Dibya Kirti Mishra of the Aryabhatta Research Institute of Observational Sciences (ARIES), an autonomous institute under the Department of Science and Technology. It involved IIST, the Southwest Research Institute (USA) and the Indian Institute of Astrophysics, and was published in The Astrophysical Journal.
☀️ Solar Cycle Context
The solar cycle is an approximately 11-year cycle of changing solar magnetic activity. Long archives such as KoSO are used to study solar cycle evolution and space weather.
📌 Key Points (Important Facts for Exams)
• AI (U-Net model) analysed KoSO hand-drawn suncharts (1904–2022).
• Plages are bright regions in the Sun’s chromosphere linked to strong magnetic fields.
• A butterfly diagram tracks latitude-wise movement of solar activity over time.
• Study led by ARIES (under the Department of Science and Technology).
• Published in The Astrophysical Journal; solar cycle is ~11 years long.
🎯 Conclusion
By applying modern AI to a century of hand-drawn solar records, the study transforms KoSO’s historic archive into a continuous digital dataset — aiding research on solar cycles, magnetic activity and space weather.
📝 Practice MCQs
Q1. The Kodaikanal Solar Observatory (KoSO) is located in which state?
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Q2. Which AI architecture was used to analyse the digitised suncharts?
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Q3. Plages are best described as:
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Q4. The chart used to track latitude-wise migration of solar activity is called a:
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Q5. The study was led by a researcher from which institute?
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Q6. ARIES functions under which department of the Government of India?
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Q7. The findings were published in which journal?
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Q8. U-Net is primarily used for which machine learning task?
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Q9. The AI-analysed observations covered how many solar cycles?
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Q10. The solar cycle is approximately how long?
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