WHEN DIBYENDU Nandi’s prediction about an intricate structure of the corona found a qualitative match in the observations of Monday’s solar eclipse, the ones who cheered the most were scientists associated with the Aditya-L1 mission, India’s first exploratory mission of the Sun that is scheduled to be launched in 2020. Nandi, who heads the Centre of Excellence in Space Sciences at Indian Institute for Science Education and Research (IISER) in Kolkata, had made predictions about the appearance of the corona during the eclipse and, while data on the raw images is still being analysed carefully, the initial findings show a “qualitative match”. “The qualitative match between the predicted and observed image is quite satisfactory,” Dipankar Banerjee, Chair of the Science Group on Visible Emission Line Coronograph (VELC), the main payload on Aditya-L1 mission, told The Indian Express. Banerjee, an expert on the solar corona at the Indian Institute of Astrophysics in Bengaluru, said that a detailed comparison can be made once the processed images are available in a few days’ time. Nandi’s group had simulated the coronal structures corresponding to the total eclipse time, a few days before August 21, based on a model developed at CESSI-Kolkata prior to August 16, Banerjee said. The Aditya satellite will carry seven scientific payloads. “One of them is a coronograph that artificially creates a total solar eclipse in space by occulting the emission coming from the solar disk. This payload called VELC will have the ability to measure the magnetic field in the corona along with the topological structure which is very similar to the modelled images of Nandi’s team. Hence, a direct comparison of the observed image and the models will enable the community to understand the structure of the magnetic corona. This kind of modelling will be very helpful for the Aditya-L1 space mission,” Banerjee said. At Inter University Centre for Astronomy and Astrophysics in Pune, associate professor Durgesh Tripathi, who is also working on the Aditya-L1 mission, told The Indian Express that the aim was to observe the sun to understand its influence on space environment and earth’s climate. “The results from the eclipse are very encouraging for the Indian team and we are very excited. The theoretical, computational models developed indigenously will complement these observations and help us interpret data from the VELC and other instruments on board the Aditya-L1 mission,” he said. Nandi’s team from CESSI had predicted an intricate structure of the corona that is a result of computing the evolution of the magnetic fields of sunspots on the solar surface over many years. “We are getting close to realistic models of the sun’s magnetic field, which are otherwise very difficult to measure. We are now in a position to make predictions about the space environment,” Nandi, who is also an associate at IUCAA, said.
