New high-resolution images of the sun show what a frightening sunspot looks like in close-up

One of the most powerful solar observatories in the world recently completed a major upgrade. And now, the GREGOR Solar Telescope in Spain has taken some of the most high-resolution images of our sun obtained in Europe.

In the new images of the upgraded telescope, details as small as 50 kilometers (31 miles) wide can be discerned amid the oscillating activity on the sun’s surface.

“This was a very exciting project, but also a very difficult one,” said physicist and chief scientist for GREGOR Lucia Clint of the Leibniz Institute for Solar Physics (KIS). “In just one year we have completely redesigned the optics, mechanics and electronics to achieve the best possible image quality.”

GREGOR (left) and its redesigned optics (right). (KIS)

Interestingly, while COVID-19 lockdowns have been a barrier to scientific research, in this case they have proven beneficial. According to a post on the KIS website, scientists were stranded at the observatory during the March lockdown in Spain. Instead of wasting time, they created the optical laboratory.

They were able to correct two important problems introduced by a pair of mirrors, coma and astigmatism, which resulted in blurry and distorted images. Because of the design of the Optical Lab, and the limited space in it, these mirrors had to be completely replaced with off-axis mirrors, finely polished to about 1/10000 the width of a human hair.

Snow storms hampered observations for a while, but when Spain reopened in July, the first thing the GREGOR team did was operate the upgraded telescope.

(KIS)

The first new photograms show solar grains, the tops of convective cells in the solar plasma. Amidst each grain lighter; This is where the hot plasma rises from below. This plasma moves outward as it cools, and then falls back into depth at the darker edges of each grain.

It’s a bit like popcorn, but don’t be fooled – a typical pellet has a diameter of around 1,500 kilometers (930 miles), which is just over 10 percent of the Earth’s diameter.

Another photo and video shows the only sunspot that covered the face of the sun on July 30, 2020. This is a temporary region where the sun’s magnetic field is particularly strong, dampening the natural convective activity of the surface; It appears darker on the surface of the sun because it is colder than the surrounding materials.

(KIS)

These sunspot regions are of great interest to us, because these magnetic field lines are exploding, entangling, and reconnecting. Magnetic reconnection results in the release of copious amounts of energy, resulting in solar flares and coronal mass ejections – a phenomenon that could affect us here on Earth, disrupting navigation and satellite communication.

Images such as those obtained by GREGOR, and other high-resolution solar observatories such as Daniel K. Inouye Solar Telescope in Hawaii, at a resolution of 30 kilometers, along with the Big Bear Solar Observatory in the United States, can help us better understand these solar processes.

Plus, we’ll never tire of looking at the amazing photos of our Sun’s surface.

A paper describing the telescope upgrade was published in Astronomy and Astrophysics.