Astronomers develop new technology and capture the most detailed images ever taken of the Sun

The surface of the Sun is a constantly shifting scene of massive sunspot groups and magnetic turmoil. Scientists want, and need, high-resolution images of the Sun, but it’s tricky because the Earth’s atmosphere makes things look blurry.

Big solar telescopes can sharpen these images of the Sun by using special computer techniques, but they usually can only do this for a small part of the image – like looking through a straw.

In this study, scientists used a telescope in Spain and tried something new: they worked on making wide pictures of the Sun in very high resolution, rather than just a tiny patch, by developing a new high-tech camera system.

Their work with the long-standing Vacuum Tower Telescope (VTT) at the Observatorio del Teide on Tenerife has produced high-resolution images that capture both small details and large-scale structures of the Sun’s active surface.

Smarter, better images of the Sun

The VTT has been in operation since 1988 and offers a rare combination: a large field of view and fine spatial resolution.

This makes it perfect for bridging the gap between images from smaller, wide-view space telescopes and large ground-based ones that focus on tight details. The new camera system now enables it to live up to that potential fully.

To reconstruct a single image, the system takes 100 short-exposure frames, each 8,000 × 6,000 pixels, recorded at a rate of 25 frames per second. These are then processed to filter out the blurring effects caused by Earth’s atmosphere.

The result? Sharp, 8K-resolution images that can show features on the Sun’s surface down to 100 kilometers in size.

For the first time, the full field of view of the VTT is restored – a significant leap forward in solar observation.

Following solar activity in real time

Thanks to this setup, scientists can now monitor the evolution of solar features every 20 seconds. That kind of temporal precision is key to understanding the Sun’s rapid and often chaotic changes.

“In order to better understand solar activity, it is crucial not only to analyze the fundamental processes of the fine structure and the long-term development of global activity with various instruments, but also to investigate the temporal evolution of the magnetic field in active regions,” explained Rolf Schlichenmaier, scientist at the Institute for Solar Physics (KIS) in Freiburg.

The upgraded view covers about 1/7 of the Sun’s diameter, or roughly 200,000 kilometers (125,000 miles) across.

That’s more than double the field typically offered by large solar telescopes, which generally capture areas about 75,000 kilometers (46,500 miles) wide.

This broader window allows scientists to trace patterns like plasma motion and sunspot development on a much larger scale.

Sharper images of the Sun’s surface

The observations made using the G-band wavelength shed new light on how sunspots fit into the broader solar convection pattern known as supergranulation.

Researchers also noticed twisted penumbral filaments – signs of the tangled magnetic fields responsible for multiple solar flares in that region.

“Our expectations of the camera system were more than fulfilled right from the start,” said Robert Kamlah, who developed the system as part of his doctoral work at AIP and the University of Potsdam.

Special filters helped make faint magnetic structures stand out as bright areas in the images. Time series in the calcium line (393.3 nm) and the Fraunhofer G-band (430.7 nm) allowed researchers to pinpoint areas of heightened solar activity

They could also trace plasma movement in different layers of the Sun’s atmosphere, from the photosphere up to the chromosphere.

New tricks for a veteran telescope

Alongside the new camera system, the VTT also hosts instruments like HELLRIDE, LARS, and FaMuLUS. These tools, operated by TLS, KIS, and AIP, respectively, work together to deliver an even more detailed picture of the Sun’s behavior.

“The results obtained show how, together with our partners, we are teaching an old telescope new tricks,” commented Carsten Denker, head of the Solar Physics Section at the AIP.

Telescopes like the VTT remain essential, especially when it’s important to capture both the large and small features of an active solar region during events like solar flares and eruptions.

Looking ahead, the researchers believe affordable CMOS camera systems with 8K resolution will be vital for the next generation of solar telescopes.

These will triple the field of view compared to current 4K setups, bringing scientists even closer to watching the Sun in full action.

from the Leibniz Institute for Astrophysics Potsdam (AIP), the Institute for Solar Physics (KIS) in Freiburg, and the Thuringian State Observatory Tautenburg (TLS), along with collaborators from the University of Potsdam,

The full study was published in the journal Solar Physics.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–