Astronomers create first detailed map of sun's coronal magnetic fields

Researchers at the U.S. National Science Foundation National Solar Observatory have successfully mapped the magnetic fields of the sun's atmospheric corona using the NSF Daniel K. Inouye Solar Telescope, the world's most powerful solar telescope. This breakthrough allows for closer study and tracking of solar space weather, which can impact Earth's technology-dependent society, from disrupting satellites to disabling power grids.

Rather than focusing solely on the sun's surface behavior, mapping the magnetic activity in the sun's corona — the atmosphere above the surface — is a crucial advancement in solar physics. Using a technique called coronagraphy to create an "artificial eclipse," scientists at the NSF Inouye Telescope detected extremely faint polarized signals around the sun, allowing them to study coronal properties that are typically only detectable during a natural eclipse. The results were published in Science Advances.

The complex dynamics of the corona's magnetic fields generated from surface sunspots can fuel explosive solar storms, flares and coronal mass ejections. Accurately mapping these developments is essential for predicting and preparing for space weather events and can help protect technology on Earth and keep astronauts safe in space. Such solar events can develop within days or weeks and are driven by the 22-year solar cycle, making accurate magnetic map readings crucial to understanding short- and long-term solar developments.

"Just as detailed maps of the Earth's surface and atmosphere have enabled more accurate weather prediction, this thrillingly complete map of the magnetic fields in the sun's corona will help us better predict solar storms and space weather," says Carrie Black, program director for the NSF National Solar Observatory. "The invisible yet phenomenally powerful forces captured in this map will propel solar physics through the next century and beyond."