Astronomers are one step closer to understanding one of the Sun’s most elusive mysteries with unprecedented data on the Sun’s magnetic field. Groundbreaking data collected by the US National Science Foundation’s (NSF) Daniel K Inouye Solar Telescope (DKIST) in Hawaii (the world’s most powerful solar telescope) has provided the most detailed images ever of the sun’s so-called “quiet” magnetic field. surface.

An international team of scientists, including researchers from the University of Sheffield, believes these data hold clues about how to model energy transfer between the Sun’s layers. The study was published on: Astrophysics Journal Letters.

This could help explain one of the biggest puzzles in astrophysics: why the Sun’s outer layer (“corona”) is hundreds of times hotter than the surface (“photosphere”) when the opposite is expected.

Senior co-investigator Professor Robertus Erdely, from the University of Sheffield’s School of Mathematics and Statistics, said: “Observations have revealed and confirmed the serpentine topology of the magnetic field in the lower solar atmosphere, also commonly referred to as the chromosphere. Understanding the geometry of the magnetic field enables us to understand the various energy phenomena that drive plasma dynamics in the solar atmosphere.” is fundamental to understanding.

“This involves a highly desirable magnetic behavior that may be responsible for amplifying solar plasma to temperatures of millions of Kelvin. These magnetic fields are also believed to cause the largest and most powerful explosions in our solar system, coronal mass ejections (CMEs).”

DKIST, which will open in 2022, is the most powerful solar optical telescope in the world. This makes it possible to surpass record solar observations from London with a resolution equivalent to a Manchester 50p coin.

A project led by King’s University Belfast in collaboration with the University of Sheffield, the NSF National Solar Observatory, the California State University High Altitude Observatory, the Max Planck Institute for Solar System Research in Germany and Etwes Lorand University in Hungary has harnessed this power. revealing a new, complex, tortuous energy structure in the magnetic field.

In the past, much research on thermal exchanges between the corona and photosphere has focused on “sunspots,” highly magnetic and active regions, often comparable in size to the Earth, that can act as conduits for energy transfer between the Sun’s outer surface. layers. .

Just beyond the sunspots, the so-called “silent sun” is covered with convective cells known as “lumps”, often the size of France, that contain much weaker but more dynamic magnetic fields that may hold the secrets to balancing the energy balance. chromosphere

Most observation reports over the past decade have revealed that magnetic fields are arranged in small loops in the quiescent photosphere. The researchers discovered something unexpected with DKIST, finding the first evidence of a more complex pattern corresponding to a snake-like change in magnetic orientation.

Professor Michael Matioudakis, co-investigator of the study and director of the ARC at Queen’s, said: “The more complex the small changes in the direction of the magnetic field, the more likely it is that energy will be released through a process we call magnetic reconnection.” – When two magnetic fields directed in opposite directions interact and release energy that contributes to the heating of the atmosphere.

“We have used the world’s most powerful solar optical telescope to reveal the most complex magnetic field orientations ever observed at the smallest scales. This brings us closer to understanding one of the biggest puzzles in solar research.”

Professor Erdely added: “Thanks to this research, we can get one step closer to understanding our life-giving star, the Sun.

“These are spectacular results brought together by junior and senior scientists from a wide range of institutions on both sides of the Atlantic. The DKIST solar telescope, the largest of its kind, has opened revolutionary new avenues in solar physics.”