New data from the DKIST solar telescope gives astronomers a more detailed understanding of the Sun’s magnetic field
Astronomers are getting closer to understanding one of the sun’s most mysterious features by collecting data on its magnetic field. The DKIST solar telescope, the most powerful in the world, has provided the most detailed information about the “quiet” surface of the Sun and its magnetic field. This may help explain one of the biggest mysteries in astrophysics – why the outer layer of the Sun (the corona) is hundreds of times hotter than its surface (the photosphere), although it would be logical to expect the opposite.
Professor Robertus Erdelyi, a senior research fellow at the Sheffield School of Mathematics and Statistics, said the observations showed a snake-like magnetic field topology in the sun’s lower atmosphere, known as the chromosphere. Understanding the geometry of the magnetic field is fundamental to elucidating the various energy processes that govern plasma dynamics in the solar atmosphere. This includes the expected behavior of the magnetic field, which may explain why solar plasma reaches millions of degrees Kelvin. It is assumed that these magnetic fields are also capable of causing the most powerful coronal ejections.
Using the DKIST solar telescope
The DKIST Solar Telescope, launched in 2022, is the most powerful solar optical telescope on Earth. Its resolution would allow a 50 pence coin (28 mm) to be seen from as far away as Manchester to London.
Previous research focused on “sunspots”—large, active areas with strong magnetic fields that can transfer energy between the layers of the Sun. However, now scientists have turned their attention to the “quiet sun” – areas without sunspots and with less intense but dynamic magnetic fields. A clear understanding of the magnetic field structure in this region could reveal the secrets of the energy balance in the solar chromosphere.
Thanks to DKIST, scientists have discovered an unexpected complexity in the structure of the quiet sun’s magnetic field: snake-like structures. Professor Michael Mathioudakis, co-author and director of the Center for Astronomical Research in Belfast, notes that the more complex magnetic field may be due to the process of magnetic reconnection, where magnetic fields pointing in opposite directions interact and release energy, helping to warm the photosphere. These new observations bring us closer to understanding one of the most significant mysteries in solar research.
