New Simulations Reveal How the Sun Keeps Its Giant Plasma Structures Alive

by Robert Schreiber
Berlin, Germany (SPX) Apr 23, 2026
At more than one million degrees, the Sun's atmosphere - the corona - is incredibly hot. Yet enormous, cool structures of solar plasma at around 10,000 degrees repeatedly appear within it. Known as prominences, these structures span up to several thousand kilometers and often resemble flickering flames in a wide variety of shapes. Despite their delicate appearance, they are massive chunks of matter: their density exceeds that of the surrounding corona by more than a hundredfold - as if a giant mountain were suspended in mid-air.

Prominences can remain stable for weeks or even months, yet they also carry explosive potential. If they do not fade away quietly, they culminate in massive eruptions during which the Sun hurls charged particles into space. A particle cloud spreading toward Earth can trigger violent solar storms. "To protect Earth's infrastructure in time, reliable forecasts of dangerous space weather are needed. A deeper understanding of prominences is a crucial piece of the puzzle," says Sami K. Solanki, Director of the Sun and Heliosphere Department at MPS and co-author of the new publication.

In a new study published in the journal Nature Astronomy, researchers at the Max Planck Institute for Solar System Research (MPS) in Germany investigate how prominences form and what accounts for their longevity. Their findings reveal that multiple processes are at work, creating a constant balance between material loss and supply.

Using complex computer simulations, the researchers model the interaction of magnetic fields and plasma within the Sun. Crucially, they consider not only the Sun's atmosphere where prominences manifest, but for the first time also the deeper, cooler layers of the star. There, beneath the visible surface, turbulent plasma flows generate the Sun's constantly changing magnetic field, which extends into the corona.

"In the Sun's atmosphere, the magnetic field is the driving force. It also plays a decisive role in all processes that contribute to the formation and maintenance of the prominences," says MPS scientist Lisa-Marie Zessner-Ondratschek, first author of the publication. Also decisive is the temperature gradient within these layers: the chromosphere reaches a maximum of 20,000 degrees, while the underlying solar surface reaches just 6,000 degrees.

For her calculations, Zessner-Ondratschek focused on smaller prominences extending up to 20,000 kilometers into the corona. She assumed a magnetic field architecture commonly associated with prominences: field lines forming a double arch in the corona, with the prominence forming in the dip between the two humps.

The simulations show that an injection process sets the prominence in motion. Driven by turbulent, small-scale magnetic field movements, the chromosphere ejects bursts of cool plasma that remain trapped in the magnetic field dip in the corona. Sophisticated supply logistics then keep the prominence alive. Although some of the cool plasma repeatedly rains back down into lower layers, two processes compensate for the losses: material is regularly ejected from the chromosphere, and - to a lesser extent - hot plasma flows from the corona along magnetic field lines into the dip, cools down, and condenses there.

"Our calculations show, more realistically than ever before, how both processes interact to supply the prominences with material and thus keep them alive," says Zessner-Ondratschek. Earlier simulations had only modeled condensation in the corona. The new results close a major gap in solar physics and demonstrate that processes within the Sun's interior are also crucial for understanding - and perhaps one day predicting - the eruptive nature of our star.

Research Report:Self-consistent numerical simulations for the formation and dynamics of solar prominences