Researchers unlock decades-old mystery of how magnetic waves heat the sun
In a ground-breaking discovery, researchers have discovered that the magnetic waves crashing through the Sun may be the key to heating its atmosphere and propelling the solar wind. Though the theory of heat being produced by the waves was predicted almost 75 years ago, the scientists have the proof for the very first time.
In a ground-breaking discovery, researchers have discovered that the magnetic waves crashing through the Sun may be the key to heating its atmosphere and propelling the solar wind.
Researchers belonging to Northern Ireland’s Queen's University led an international team to uncover the mystery of how magnetic waves heat the sun. The research paper was published in a journal called Nature Physics.
• The Sun is the source of energy that sustains all life on Earth but much remains unknown about it.
• In 1942, Swedish physicist and engineer Hannes Alfvén predicted the existence of a new type of wave due to magnetism acting on a plasma, which led him to win the Nobel Prize for Physics in 1970.
• Since his prediction, Alfvén waves have been associated with a variety of sources including nuclear reactors, the gas cloud that envelops comets, laboratory experiments, medical MRI imaging and in the atmosphere of the Sun.
• Scientists suggested for many years that these waves may play an important role in maintaining the Sun's extremely high temperatures but had not been able to prove it until now.
Speaking on the same, Dr. David Jess from the School of Mathematics and Physics at Queen's University Belfast said, "For a long time scientists across the globe have predicted that Alfvén waves travel upwards from the solar surface to break in the higher layers, releasing enormous amounts of energy in the form of heat. Over the last decade scientists have been able to prove that the waves exist but until now there was no direct evidence that they had the capability to convert their movement into heat.”
• The study used advanced high-resolution observations from the Dunn Solar Telescope in New Mexico (USA) alongside complementary observations from NASA's Solar Dynamics Observatory to analyse the strongest magnetic fields that appear in sunspots.
• The sunspots have intense fields similar to modern MRI machines and are much bigger in size than the Earth.
• By breaking the Sun's light up into its constituent colours, the international team of researchers was able to examine the behaviour of certain elements from the periodic table within the Sun's atmosphere, including calcium and iron.
• Once these elements had been extracted, intense flashes of light were detected in the image sequences.
• The intense flashes showed the properties of the Alfvén waves converting their energy into shock waves. The shock waves then ripple through the surrounding plasma, producing extreme heat.
• Using supercomputers, the researchers were able to analyse the data and show for the first time in history that the Alfvén waves were capable of increasing plasma temperatures violently above their calm background.
Though the theory of heat being produced by the Alfvén waves was predicted almost 75 years ago, the scientists have the proof for the very first time.
The research opens up a new window to understand how the phenomenon could potentially work in other areas such as energy reactors and medical devices.
The International Team
The team included universities from across the world including Queen's University Belfast, Austria’s Space Research Institute, Ilia State University in Georgia, Spain’s Instituto de Astrofísica de Canarias and American institutions including Lockheed Martin, California State University Northridge and National Solar Observatory.