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New images of the sun’s surface captured by a powerful ground-based solar telescope have revealed sunspots and other features in unprecedented detail.
Although the sun is becoming increasingly active as the July 2025 solar maximum — the peak of the sun’s 11-year cycle — draws closer, the photos showcase the quieter aspects of the solar surface.
Cool, dark sunspots dot the photosphere, or the sun’s surface where the magnetic field is strong, and they can be the size of Earth or larger. Clusters of sunspots are the cause of solar flares and coronal mass ejections — when plasma and part of the magnetic field pinch off from the sun’s outer atmosphere, or corona, and go streaming across the solar system.
These energetic outbursts from the sun can impact Earth’s satellite-based communications.
The sunspot regions shown in the images are a study in contrast. Bright hot plasma flows upward on the sun’s surface, while darker, cooler plasma flows down. In the chromosphere, the atmospheric layer above the surface, threadlike structures reveal the presence of magnetic fields.
Fine, detailed structures, including glowing dots that exist where the magnetic field is the strongest, can be seen in the dark sunspots. Bright strands derived from the magnetic field called penumbral filaments, which transport heat, surround the sunspot.
Another image shows a sunspot that has lost the majority of its brighter, surrounding region, or penumbra, which seems to be decaying. Researchers believe the remaining fragments could be the end point in the evolution of a sunspot, before it disappears.
The Inouye Solar Telescope also glimpsed “light bridges,” bright solar features that span the darkest region of a sunspot. These complex structures can differ in appearance, but scientists think light bridges could signal that a sunspot is about to decay. Future observations could provide more data about the formation of light bridges and their significance.
The images taken over the past year were among some of the first observations using the world’s largest and most powerful ground-based solar telescope during its commissioning phase, according to the National Science Foundation. Currently, the telescope is being brought up to its full operational capabilities, according to the agency.
Scientists hope the telescope’s capabilities will allow them to answer key questions about the sun, including the origin of solar storms, as well as unlock the complexities of its magnetic field.
The telescope was designed to make ongoing measurements of the magnetic fields in the sun’s corona and provide images of the solar atmosphere like never before. Compared with other observatories’ imaging capabilities, Inouye can capture solar features three times smaller.
Solar data from the Inouye Solar Telescope, as well as two space-based missions called Solar Orbiter and the Parker Solar Probe, can help unravel some of the sun’s enduring mysteries — all while providing stunning views of our star in a new light.