As a total solar eclipse will be visible in parts of Europe on August 12 for the first time since 1999, solar physicists at the Raman Research Institute (RRI) in Bengaluru, along with collaborators, have predicted the magnetic structure of the Sun’s outer atmosphere, or its ‘crown’, called the corona, during the eclipse.
On the day of the eclipse, their prediction indicates the presence of multiple large-scale petal-like structures and more local, elongated petals. If this turns out to be true, the Sun’s corona during the August 12 eclipse would be quite complex and spectacular, according to a statement from RRI.
Why study the sun’s corona?
The solar corona is very faint compared to the bright solar surface. It is extremely hard to observe the corona unless an object occults the bright solar disk. This occulting object can be the Moon while passing in front of the Sun, or an artificial disk mounted on a satellite — a coronagraph. Hence, a total solar eclipse, when the Moon occults the Sun, offers the best chance to observe the corona from the ground, and test theories and models.
A file photo of a total solar eclipse seen from Arlington, Texas, on April 8, 2024.
| Photo Credit:
Julio Cortez
These models are essential in understanding the origin of solar storms, solar flares and coronal mass ejections. The eruption of plasma and charged particles from the Sun during these events affects the Earth’s outer atmosphere and its technologies, leading to power outages and disruption of communication and GPS networks. They can damage satellites and harm astronauts orbiting around the Earth through doses of high radiation and energetic particles.
To better understand and predict these phenomena, theorists and modellers use physics and computer simulations to recreate and study the Sun’s behaviour. More accurate models can help explain how solar storms form and improve scientists’ ability to forecast these powerful eruptions.
Novel approach
The research group of Dibyendu Nandi, senior professor in the Astronomy and Astrophysics theme at RRI, is one of the groups across the globe that pursue the testing of computational models of solar magnetism and space weather through eclipse observations.
The team utilised a novel approach that employs two distinct computational models, rooted in the theoretical framework proposed by Nandi and colleagues, to predict the structure of the Sun’s coronal magnetic field.
A data-driven model with built-in memory spanning multiple years was utilised for the prediction. Using data available up to August 10, 2026, the researchers used the model to predict what the Sun’s magnetic field distribution would be on August 12, 2026.
This model is run forward to August 12 to predict the Sun’s surface magnetic field distribution on that day, incorporating data from the solar surface as observed until August 10.
“Calibrating the model with past solar observations is essential to obtain accurate estimations,” said Nandi.
“We strive to continuously improve our models by comparing our simulated predictions with observations – the best test for any theoretical model. Improved modelling approaches and constraining their underlying theoretical ideas help us build better models for predicting solar magnetic field dynamics and space weather,” he added.
The forecasting team led by Nandi included Sagnik Saha from the Raman Research Institute, Priyansh Jaswal from the Centre of Excellence in Space Sciences India at IISER Kolkata, Shaonwita Pal from the Indian Institute of Astrophysics and Department of Technical Education and Skill Development, Government of West Bengal, Soumyaranjan Dash from the United States National Solar Observatory, and Chitradeep Saha from the University of Reading, UK.
A rare event, invisible from India
In a total solar eclipse, the entire visible disk of the Sun is occulted by the Moon, turning day into night for a few minutes.
The eclipse will start at 9.04 pm IST on August 12, 2026. The Moon’s shadow will cover the Sun for two minutes and 18 seconds.
The eclipse won’t be visible from India as it will be night by then. While most of Spain will get to see the total solar eclipse, other parts of Western Europe, parts of northwestern Africa, and some parts of the U.S. will see a partial solar eclipse.
Published – August 12, 2026 05:04 pm IST
