The Sun, the brightest object in the sky, has captivated humanity since the origins of our species. While the scientific knowledge that the scientific study of the Sun has brought us over the past hundreds of years has allowed us to get very close to understanding our star, there are still unsolved puzzles.
One of the most challenging puzzles is what heats up the Sun’s corona, which is 300 times hotter than its surface. The Sun has a temperature of approximately 5500 ° C, while the layer of gas that we call the corona is at a temperature of almost two million degrees. No one has found a satisfactory solution to this question.
However, a lot has been theorized on the subject. One possible explanation for the existence of much more energy in the Sun’s magnetic field would imply the existence of numerous small explosions, which occur in the star continuously. Each of these blasts would be too weak, but they would all have enough energy to heat the entire corona.
Many attempts have been made to search for X-rays and ultraviolet light to indicate the presence of these explosions, and none have been successful. Therefore, it was concluded that, if they exist, these small explosions are too faint to be detected even by the best instruments available today. These explosions would also give rise to small flashes of radio lights, but until now there were no telescopes sensitive enough to detect them.
So far: a new study reports the detection of the first radio flashes that could demonstrate the existence of ‘mini-explosions’ that heat the solar corona.
A group of scientists from the National Center for Radio Astrophysics (NCRA), part of the Tata Institute for Fundamental Research, have discovered tiny flashes of radio light from around the Sun. These are the first evidence for the existence of tiny magnetic bursts, and they may give solution to the classic problem of the hot corona. However, although scientists have already discovered that the additional energy that heats the corona must come from solar magnetic fields, it is not yet known exactly how it happens.
This detection was made possible by data from a new instrument, the Murchison Widefield Array (MWA), and years of work at NCRA-TIFR that have resulted in the most accurate images of the Sun’s radiation ever obtained.
According to study co-author Dr. Atul Mohan: “What makes this research really exciting is that these flashes are present everywhere on the Sun and at all times, even in regions of weak magnetic fields, the so-called regions of the Earth. ‘Silent Sun’ “.
He adds: “Preliminary estimates suggest that these small magnetic bursts should collectively have enough energy to overheat the corona , which is exactly what is needed to solve the coronal heating problem.”
References:
Surajit Mondal, Divya Oberoi, and Atul Mohan. ‘First Radio Evidence for Impulsive Heating Contribution to the Quiet Solar Corona’ (2020 June 1) The American Astronomical Society. http://dx.doi.org/10.3847/2041-8213/ab8817
