Scientists capture deepest radio images of the Sun

Manasi Saraf Joshi
Wednesday, 17 April 2019

This is a big step towards predicting space weather

Pune: For the first time, a team of Indian scientists along with their international counterparts were able to capture the deepest ever images of the Sun at radio wavelength. This will help to understand space weather, which in turn will help to better understand and predict weather on the Earth.
A team of scientists led by Divya Oberoi at National Centre for Radio Astrophysics (NCRA) along with Atul Mohan and Surajit Mondal have made significant advances by making the deepest ever images of the Sun at radio wavelengths.

The Sun hosts several mysteries even today, like when and how powerful explosions take place in the Sun which can potentially affect communication satellites, power supply, GPS navigation, etc. on Earth. 

Speaking with Sakal Times, Oberoi said, “These images are 1,00,000 times better than the images taken before in contrast. By contrast I mean that we were able to capture the faint features on the Sun.” He said, “Enormous explosions take place on Sun throwing out plasma, which affects the space weather. Plasma means gases. Whether this plasma is bad or better depends on the magnetic field. Eventually, this technique would allow us to know the severity of these plasmas.”

Oberoi was working at Massachusetts Institute of Technology (MIT) in US, where in 2004 the idea of this project took place. “I along with some 100 other scientists from across the globe were working on this model and from 2013, we started collecting the data, understanding it, developing software  started. Before that in 2012, I moved to NCRA but continued to work on it,” he said. 

When asked what would be the next step, he said, “This will help us understand the impact of solar activities on Earth. As light has two polarisations, we need to detect the polarisation where the magnetic field is After detecting it, we can know about the magnetic field and its strength,” he explained. 

Techniques used 
The radio data was acquired through the radio telescope Murchison Widefield Array (MWA) in Australia, where Oberoi was involved since its inception. Oberoi and his PhD students Rohit Sharma, Atul Mohan and Surajit Mondal developed an indigenous software package called ‘Automated Imaging Routine for Compact Arrays for the Radio Sun’ or AIRCARS. The lead author of the AIRCARS project, Surajit Mondal said, “Previously people could look at only the bright flares of the Sun, which is the tip of the iceberg. For understanding the space weather what was needed were the details hidden in the faint end.” AIRCARS can do exactly this which can help in understanding and predicting the space weather better and faster than previously possible.

Atul Mohan, the lead author of the paper, said, “These findings dismiss the surface origin of the oscillations, instead point to new phenomenon operating deep down the solar atmosphere.”

Both these studies will appear in the April issue of the prestigious Astrophysical Journal of the American Astronomical Society. 

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