This marvelous image of a sunspot was captured by the world's largest solar observatory, the National Science Foundation's Daniel K. Inouye Solar Telescope on the island of Maui, Hawai'i. From the National Solar Observatory, the organization that built and operates the telescope:
"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 [National Solar Observatory associate director Thomas] Rimmele.
The image reveals striking details of the sunspot's structure as seen at the Sun's surface. 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.
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 is still extremely hot with a temperature of more than 7,500 degrees Fahrenheit.
This sunspot image, measuring about 10,000 miles across, is just a tiny part of the Sun. However, the sunspot is large enough that Earth could comfortably fit inside.
Inouye Solar Telescope Releases First Image of a Sunspot (NSO.edu)