NCRA scientists from Pune discover solar ‘smoking guns’: small magnetic explosions spread all over the Sun
The scientists have likened the flashes to smoking guns of small magnetic explosions, which according to the researchers, is the first evidence of its existenceUpdated: Jun 03, 2020 16:51 IST
Using the available data from Murchison Widefiled Array (MWA), a low frequency radio-telescope located in Western Australia, a team of scientists at the National Centre for Radio Astrophysics (NCRA), Pune, have, through observation, discovered tiny flashes of radio light emanating all over the Sun.
The scientists have likened the flashes to smoking guns of small magnetic explosions, which according to the researchers, is the first evidence of its existence.
“It also explains a long-pending coronal heating problem of the Sun,” a release from the NCRA said on Tuesday.
A consortium of partner institutions from seven countries, comprising hosts Australia, USA, India, New Zealand, Canada, Japan, and China have financed the development, construction, commissioning, and operations of the MWA facility.
These findings come after research on the topic was carried out for a span of nine months by Phd student Surajit Mondal.
His work has been entitled ‘The first radio-evidence for impulsive heating in the quiet solar corona’.
The research was completed under the supervision of Divya Oberoi, a faculty member at NCRA, along with Atul Mohan, a former student at NCRA, now at the Rosseland Centre for Solar Physics, Norway.
Mondal (29), said, “The goal of the project was to understand that why the outer layer of the Sun has temperatures 1,000 times hotter than the surface of the Sun. This was what the research community were trying to understand for the past 50 years.”
“Most of the solar surface has weak magnetic fields and in the regions where the magnetic field was weak, it was not known how the magnetic field had energy,” Mondal said, explaining further, “The question before us was to how to extract the energy from the magnetic field and convert it to heat energy. In regions where the magnetic field was high, heating happens impulsively. However, the regions where it was low, the exact process was not known. Our studies indicate that even when the magnetic field is weak, the heating happens impulsively. The radio lights… they actually come and go very fast and are present throughout the Sun.”
Prof Divya Oberoi said, “The breakthrough took place taking into account the availability of data from Murchison Widefield Array (MWA), and the work which we have been doing for the past few years at NCRA to build the techniques and tools to make the most sensitive solar radio images from this data. The very weak radio flashes we have discovered are about 100 times weaker than the weakest bursts reported till now. It is just that they have turned out to be more than 1,000 times weaker than his prediction and it took us a long time to find them. This is an excellent example of how progress in technology enables progress in Science.”
Atul Mohan said, “Our preliminary estimates suggest that these tiny magnetic explosions should collectively have enough energy to heat the corona, which is exactly what is needed for solving the coronal heating problem.”
The research will appear in the June issue of the Astrophysical Journal Letters of the American Astronomical Society and is available at https://iopsc ience.iop.org/article/10.3847/2041-8213/ab8817