‘Unprecedented’ high-res image of sunspot captured by new solar telescope

Sunspots — dark areas on the sun — help scientists track activity on the surface of our solar system’s star. These dark spots are the origin point for the explosive flares and ejections that release light, solar material and energy into space.

This “space weather” caused by the sun is important to understand because it can impact the power grid, satellites, GPS, airlines, rockets and astronauts working in space.

The National Science Foundation’s Daniel K. Inouye Solar Telescope, a new solar observatory based in Hawaii, has released its first image of the sun, which captures that activity in striking detail.

“While the start of telescope operations has been slightly delayed due to the impacts of the COVID-19 global pandemic, this image represents an early preview of the unprecedented capabilities that the facility will bring to bear on our understanding of the Sun,” said David Boboltz, NSF program director for the Inouye Solar Telescope, in a statement.

This image, taken on January 28, was one of the first of a new solar cycle. It was taken shortly after the sun reached its last solar minimum in December 2019, when the sun was less active and had fewer spots. Every 11 years, the sun completes a solar cycle and begins a new one.

The current solar cycle’s solar maximum — when activity peaks — is predicted to occur in mid 2025. The telescope’s 4-meter primary mirror will give the best views of the sun from Earth during this period of increasing activity on the sun’s surface.

“With this solar cycle just beginning, we also enter the era of the Inouye Solar Telescope,” said Matt Mountain, president of the Association of Universities for Research in Astronomy, the organization that manages the National Solar Observatory and the Inouye Solar Telescope, 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.”

Over the course of a solar cycle, the sun will transition from a calm period to one that is very intense and active. This activity is tracked by counting sunspots on the sun and how many are visible over time. During the peak of this activity, the sun’s magnetic poles flip. Then, the sun will grow quiet again during a solar minimum.

During the peak of solar activity in the last cycle, 120 sunspots were tracked. About 115 sunspots are predicted for the peak of this new cycle.

The new image is of an area of the sun about 10,000 miles across. While just a tiny part of the sun, the sunspot is large enough that Earth could comfortably fit inside, the Inouye Solar Telescope said in the statement.

“The sunspot image achieves a spatial resolution about 2.5 times higher than ever previously achieved, showing magnetic structures as small as 20 kilometers on the surface of the sun,” said Thomas Rimmele, the associate director at the National Solar Observatory.

The streaky appearance of hot and cool gas spidering out from the darker center is the result of sculpting by a convergence of intense magnetic fields and hot gasses boiling up from below, according to the statement.

The concentration of magnetic fields in this dark region suppresses heat within the sun from reaching the surface. Although the dark area of the sunspot is cooler than the surrounding area of the sun, it’s still extremely hot with a temperature of more than 7,500 degrees Fahrenheit, it said.

The telescope is located on the island of Maui in Hawaii and is the largest optical solar telescope in the world. Construction began in 2013 and is slated to be fully completed in 2021.