The data collected by the balloon-borne solar observatory Sunrise III reveals intricate details of the Sun’s surface.
The balloon-borne solar observatory Sunrise III captured an extraordinary dataset of around 200 terabytes during its six-and-a-half-day stratospheric flight in July this year. The research team has now released the first meticulously processed images from the telescope, along with a video of the entire flight captured by the onboard camera. The images reveal surface structures as small as 50 kilometers across. Sunrise III’s data enables researchers to observe processes on the Sun’s visible surface and its lower atmosphere with unprecedented spatial resolution over several continuous hours. During its research flight, the Sun was particularly active, displaying sunspots, dynamic magnetic fields, and even two radiation flares.
Six Days of Uninterrupted Solar Observation
For six-and-a-half uninterrupted days, Sunrise III provided an unimpeded view of the Sun during its research flight in the summer of 2024. Following a successful launch on July 10 beyond the Arctic Circle in Sweden, a helium balloon lifted Sunrise III to an altitude exceeding 35 kilometers. This observation position is ideal for solar research, being above Earth’s atmospheric turbulence and allowing access to ultraviolet solar radiation. The flight’s timing coincided with the Arctic’s midnight sun, enabling constant solar observation throughout the journey. Stratospheric winds carried the observatory westward until its landing in Canada’s Northwest Territories.
Despite the mission’s success, only a fraction of the 200-terabyte dataset has been analyzed so far. The recovery team retrieved the data storage approximately two weeks after landing. Reviewing all images taken by the telescope would take about a month if viewed at a standard video frame rate of 25 frames per second. Processing the data fully requires extensive effort due to its complexity.
Capturing Over 86 Million High-Resolution Solar Images
The first processed images offer a unique glimpse of the Sun’s visible surface and the overlying chromosphere. The UV spectropolarimeter Susi, developed under the leadership of the Max Planck Institute for Solar System Research, captures ultraviolet light from the Sun, invisible to the human eye. The instrument recorded not only sunspots and their finely structured edges but also the typical pattern of rising and falling plasma known as granulation.
Between individual granules, narrow boundary regions display tiny, bright spots in the images. Measuring just 50 kilometers across, these are considered the smallest building blocks of the Sun’s magnetic field.
“To make structures as small as 50 kilometers visible on the Sun, we push optical technology to its limits,” explains Sunrise III project scientist Achim Gandorfer. “The sensitive system must be precisely aligned during flight.” He adds, “We correct deviations in the micrometer range in real time, mainly caused by unavoidable temperature fluctuations. The final data refinement happens in a supercomputer.”
“Sophisticated algorithms and months of computing time on our institute’s high-performance cluster are required to eliminate all interfering effects from the data,” adds Tino Riethmüller from the Max Planck Institute for Solar System Research, responsible for Sunrise III’s software.
