Brilliant Sunspot Photo Captures the Beginning of a New Solar Cycle

The Inouye Solar Telescope captured the unprecedentedly detailed image of a 3,700-mile-wide sunspot on January 28

Photograph of a sunspot has a dark heart-shaped center and dark tendrils that expand into the bright orange and yellow surface of the Sun
The photograph shows an area about 10,000 miles wide, a small portion of the Sun which is 864,000 miles wide Image credit: NSO/AURA/NSF

The Sun goes through 11-year-long cycles of magnetic activity and a new one kicked off this year. Luckily, the National Science Foundation’s new Solar Telescope was ready for a test run just in time. The specialized telescope snapped a photograph of a sunspot, a concentrated patch of magnetic fields, at the end of January, and released the final image on December 3.

The telescope, which is still under construction at the summit of the Hawaiian island of Maui, captured its first series of images at the beginning of 2020, María Paula Rubiano A. reports for Popular Science. With a 13-foot-wide mirror, Inouye Solar Telecope is the largest of its kind, which has allowed it to take unprecedentedly detailed snapshots of the sun. Astronomers hope that the research enabled by the telescope will help them predict when solar activity, called “space weather,” will affect Earth.

“With this solar cycle just beginning, we also enter the era of the Inouye Solar Telescope,” says the Association of Universities for Research in Astronomy president Matt Mountain in a statement. “We can now point the world’s most advanced solar telescope at the Sun to capture and share incredibly detailed images and add to our scientific insights about the Sun’s activity.”

The first photograph released from the telescope, in late January, showed the plasma that covers the sun in what looked like kernel-shaped patches, each the size of Texas, Brigit Katz wrote for Smithsonian at the time. The image came from the same series of test photographs, Christopher Crockett reports for Science News, and the telescope is expected to be completed in 2021. But already the telescope has revealed new details about our solar system’s central figure. The kernels, for example, have bright spots wedged between them.

"As scientists, our eyes went to the brightest tiny, little features," said National Solar Observatory solar physicist Valentin Martínez Pillet to Space.com in March. "The reason for that is we know these are the roots of the solar magnetic field."

A sunspot, on the other hand, is the result of many intense magnetic fields and hot gas boiling up and preventing heat from reaching the surface. The lower temperature—7,500 degrees Fahrenheit, lower than the Sun’s usual 10,000 degrees—is shown by the darker coloring in the image. But the National Solar Observatory notes in its statement that this sunspot is different from the visible sunspots that appeared on the Sun in November and December. The sunspot photographed in January is about 3,700 miles across, per the statement. For comparison, the Earth is about 7,900 miles wide.

Researchers want to be able to predict space weather caused by magnetic fields bursting out of sunspots because of the impact those fields can have on Earthly infrastructure like power grids, satellites, GPS and satellites, Katie Hunt reports for CNN. The high-resolution images captured over the entire course of the new solar cycle, which will peak in 2025, could help researchers understand and predict future solar weather. The goal is to be able to predict solar activity 48 hours in advance instead of the current prediction time, which is only 48 minutes of warning.

The telescope’s massive 13-foot-wide mirror is about three times wider than other solar telescopes, which helps scientists achieve higher-resolution images. But the telescope’s location at Haleakalā, the peak of Maui in Hawaii, is also key to its solar photography because the location is free of dust in the atmosphere that scatters light, Ilima Loomis reported for Science magazine in 2017. Mountain peaks are sacred locations in Native Hawaiian culture; Haleakalā is the peak where the demigod Maui lassoed the Sun and bargained for it to move more slowly across the sky. The Inouye Solar Telescope was constructed despite local opposition, but practical issues made it more difficult to protest than the Thirty Meter Telescope on Mauna Kea, Science reports.

Completion of the Inouye Solar Telescope was initially planned for 2020 but was delayed by the Covid-19 pandemic. The NSF program director for the Telescope David Boboltz says in the statement, “While the start of telescope operations has been slightly delayed…this image represents an early preview of the unprecedented capabilities that the facility will bring to bear on our understanding of the Sun.”