Hawai telescope made a most detailed Sun image ever

A telescope in Hawaii made the most detailed solar photo to date. Cells of cooler and hotter plasma are visible.

We have never seen the sun so detailed. Wednesday evening the first images were presented that were made with the new Daniel K. Inouye Solar Telescope (DKIST) on the Hawaiian island of Maui. They give a spectacular impression of the swirling solar surface.

The sun has a diameter of almost 1.4 million kilometers – more than 100 earth diameters – and consists almost entirely of the gases hydrogen and helium. It is essentially a large energy plant. At its center, hydrogen is converted into helium under extremely high pressure and temperature.

A huge amount of energy is released during that process, which makes its way out. Initially this only happens in the form of radiation, but from about 175,000 kilometers below the solar surface, a different mechanism prevails: convection. As a result, the material rises from the bottom up as a result of heating, cools down when it reaches the surface and then sinks down again. This process is similar to what happens in a pan of boiling water.

Seen from above, the solar surface therefore displays a grainy pattern of angular cells – the so-called granules. The clear central part of such a cell consists of rising hot gas, the dark edge of cooler falling gas.

The photo and video taken with the new solar telescope clearly show that. The smallest details on these shots have dimensions of around 30 kilometers. The granules themselves are considerably larger: they have diameters of around 1,000 kilometers – one and a half times France.

The new solar telescope is equipped with a 4-meter main mirror, making it the largest of its kind. This mirror bundles the sunlight, which is then led to an instrument room. There, the light is split into sub-beams that go to five different cameras. These instruments not only study the surface of the sun, but also its atmosphere – including the thin corona, which is normally only perceptible during total solar eclipses.

The solar telescope is housed in a closed dome, which is covered with thin cooling plates, equipped with shutters – provisions that must stabilize the inside temperature. Because an enormous amount of heat is released when bundling sunlight, the observatory is also equipped with an extensive cooling system.

Moreover, a new solar telescope is also being worked on in Europe. This European Solar Telescope (EST) should be about the same size as the DKIST, but will look very different. Its design is derived from the Dutch Dutch Open Telescope (DOT) on the Canary Island of La Palma, which is no longer used for solar research since 2010. Just like the DOT, the EST will be placed on a platform and it will get an “open” design, whereby the air can flow freely through the telescope.

Former DOT manager, Felix Bettonvil from Leiden University, calls the recording “impressive”, all the more so because in modern solar telescopes the optics are no longer placed in a vacuum, he emails.

“That makes it much harder to get sharp images.”

Emeritus solar physicist Rob Rutten, from the Sterrekundig Instituut Utrecht, who was discontinued in 2012, agrees that DKIST shows ten times smaller details than the DOT, but adds that the latter was also ten times smaller and at least thirty times as cheap. He also made a comment about the image sharpness achieved: “I think they used the same image reconstruction technique as we at the DOT at the time. Then you have included more frames than shown in this video clip and you turn every roughly ten images into a sharper film image by eliminating rapid image disturbances from the earth’s atmosphere. ”