The findings, published in the Astrophysical Journal Letters, reveal that even the Sun’s so-called quiet regions contain elaborate magnetic structures. Sunrise-III observed numerous thin, elongated magnetic features forming part of a larger network, known as the magnetic canopy, that extends through the chromosphere, a layer of the solar atmosphere above the visible surface. Rather than forming a smooth, uniformly expanding structure, the canopy contains many narrow, thread-like elements.
Computer simulations reproduced the patterns recorded by Sunrise-III, suggesting that movements on the solar surface twist magnetic field lines, creating the intricate structures observed higher in the atmosphere. The observatory also examined another quiet region near the solar limb and measured magnetic fields within spicules, narrow jets of solar material that extend upward from the surface, revealing how magnetic field distribution changes with height.
Quiet regions cover most of the Sun and contain generally weaker magnetic fields than active areas such as sunspots. Their subtle structures are difficult to measure from the ground because turbulence in Earth’s atmosphere blurs fine details. Sunrise-III was designed to overcome this by carrying a 1-metre telescope high into the stratosphere, where atmospheric interference is greatly reduced. The gondola carried three instruments, including SCIP (Sunrise Chromospheric Infrared spectroPolarimeter), a near-infrared instrument led by NAOJ that measures magnetic fields continuously across different layers of the solar atmosphere.
The discovery offers new clues to how energy generated by motions near the solar surface is transferred into higher layers of the atmosphere, and how magnetic activity contributes to heating the Sun’s atmosphere, even in regions that appear calm when viewed from afar.