Sunrise III mission reveals high-resolution data on solar dynamics
A balloon-borne observatory captured high-resolution data on the Sun's photosphere and chromosphere during a stratospheric flight.
Sunrise III mission reveals high-resolution data on solar dynamics
A balloon-borne solar observatory has captured an unprecedented volume of data regarding the Sun's photosphere and chromosphere, offering new insights into the mechanisms driving the star's volatile outbursts. The Sunrise III mission, which launched on July 10, 2024, collected over 200 terabytes of data during a stratospheric flight lasting six and a half days.
The observatory traveled from the northernmost point of Sweden to the Northwest Territories of Canada. By operating in the stratosphere at approximately 35 kilometers above the Earth's surface, Sunrise III bypassed the majority of the atmosphere. This altitude minimized the impact of atmospheric turbulence, which typically limits ground-based telescopes to short, interrupted observations. Because the mission followed a summer flight path near the Arctic Circle, the Sun remained visible for most of the day, allowing for continuous observation series lasting several hours.
The mission focused on a layer of the Sun roughly 2,000 kilometers thick. This region, comprising the visible surface and the adjacent chromosphere, is characterized by waves, fluctuating magnetic fields, and hot plasma. These elements combine to produce the radiation and particles that the Sun hurls into space.
The observatory utilized a telescope with a primary mirror diameter of one meter and a sophisticated image stabilization system. Three specific instruments processed the captured light: the SUSI ultraviolet spectropolarimeter, the TuMag magnetograph, and the SCIP infrared spectropolarimeter. This equipment allowed the team to capture image sequences every quarter of a second, achieving a resolution of up to 50 kilometers from a distance of nearly 150 million kilometers. The instruments also detected a broad range of wavelengths, including ultraviolet light, which is normally absorbed by the Earth's ozone layer and inaccessible to ground-based telescopes.
During the flight, the observatory recorded both the Sun's quiescent state and its more temperamental activities. The data includes images of sunspots, some measuring about 10,000 kilometers in diameter, as well as various solar flares. On July 13, 2024, Sunrise III observed an M5.3-class solar flare. Using the TuMag instrument, researchers filtered different polarization states and wavelengths of visible sunlight to analyze the strength and structure of the magnetic field within the photosphere and the lowermost chromosphere.
"Sunrise III has already permanently changed our view of the Sun. The data show how minute structures and rapid processes in the photosphere and chromosphere determine the impetuous nature of our star,"
Sami K. Solanki, Director at the Max Planck Institute for Solar System Research and Sunrise III Principal Investigator
A review article summarizing the mission’s first scientific results was published today in the journal The Astrophysical Journal Letters. This review article initiates a focus issue dedicated to the Sunrise III mission, to which individual studies will be added over time.
"The results already available are as diverse as the Sun itself,"
Smitha Narayanamurthy, MPS researcher and head of Science Working Group for Sunrise III
Narayanamurthy added that the findings reveal new information about the Sun's quiescent state and help in understanding its volatile side. However, project manager Andreas Korpi-Lagg noted that only a small portion of the data has been analyzed so far. He stated that the mission's data will keep researchers busy for many years and may still hold surprises.
The Sunrise III mission is a joint effort by the Max Planck Institute for Solar System Research in Germany and the Johns Hopkins Applied Physics Laboratory in the United States. Other contributors include the Leibniz Institute for Solar Physics, the National Astronomical Observatory of Japan, and a Spanish consortium led by the Instituto de Astrofísica de Andalucía, which includes the Universitat de València, Universidad Politécnica de Madrid, the Instituto Nacional de Técnica Aeroespacial, and the Instituto de Astrofísica de Canarias. Additional partners include the Swedish Space Corporation and NASA's Wallops Flight Facility Balloon Program Office.
Funding for the project was provided by the Max Planck Foundation, the ISAS/JAXA Small Mission-of-Opportunity program, JSPS KAKENHI, and the Spanish MCIN/AEI. NASA provided support under the "Heliophysics Low Cost Access to Space" program via Grant #80NSSC18K0934 and #80NSSC24M0024.
