Scientists at the Max Planck Institute for Solar System Research have identified a continuous refill mechanism that explains how solar prominences can persist for weeks or months despite the extreme conditions of the Sun’s corona.
The study, published in Nature Astronomy, combines advanced simulations with observations to show that prominences are not static structures but dynamic systems sustained by a balance between material loss and replenishment. Cool plasma from the chromosphere is ejected upward by small-scale magnetic disturbances, becomes trapped in a magnetic dip formed by twin arches of coronal field lines, and is constantly refreshed by both new injections from below and cooling of hot plasma from above.
This process occurs in a modeled double-arched magnetic topology where the central dip acts as a cradle for dense, cool plasma — approximately 10,000 degrees Celsius — embedded within the million-degree corona. The prominence’s density exceeds that of the surrounding corona by over a hundred times, making it a massive structure suspended against gravity.
Lisa-Marie Zeßner-Ondratschek, the study’s first author, emphasized that the magnetic field is the driving force in prominence formation and maintenance, working in tandem with the steep temperature gradient between the chromosphere (peaking at 20,000 degrees) and the underlying solar surface (6,000 degrees).
By extending simulations from the corona down into the convection zone beneath the Sun’s surface, the research captures how turbulent flows reshape magnetic fields and feed energy and structure upward — a holistic approach missing in earlier models that focused only on the atmosphere and could only simulate coronal condensation.
The findings offer critical insight into solar stability and eruptive behavior. When prominences destabilize, they can erupt and launch charged particles into space, potentially triggering geomagnetic storms that threaten satellites, power grids, and communication systems on Earth.
Earlier simulations that confined their scope to the solar atmosphere failed to capture the full replenishment cycle, missing the contribution of subsurface dynamics. This study’s integration of multiple solar layers marks a significant advancement in modeling prominence lifecycles.
The research does not claim to predict individual prominence eruptions but provides a foundational understanding of why these structures endure as long as they do — knowledge essential for improving space weather forecasts.
Why do solar prominences remain cool while surrounded by million-degree plasma?
They are sustained by a continuous inflow of cooler plasma from the chromosphere, which is significantly cooler than the corona, and their magnetic topology traps and insulates this material from the surrounding heat.
How does this research improve our ability to forecast solar storms?
By revealing the physical mechanisms that govern prominence stability and eruption, the study contributes to better modeling of solar instabilities that can lead to Earth-directed coronal mass ejections.
What role does the Sun’s magnetic field play in prominence formation?
The magnetic field shapes the double-arched structure that creates a dip where cool plasma collects, and it governs the movement and trapping of plasma essential to the prominence’s existence and longevity.
