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Home / Science / Astrophysicists have just seen a stunning structure in the outer atmosphere of the sun

Astrophysicists have just seen a stunning structure in the outer atmosphere of the sun



The sun is a gigantic, whirling ball of gases, in an atmosphere that throws streamers and lumps of particles into space. Now astrophysicists have discovered that in the solar atmosphere, something that may seem like cosmic disorder hides a beautiful order.

Above all, they found and illustrated finely detailed streamers, blobs and puffs that emerge in the outer corona. The solar atmosphere, which begins about 2,100 kilometers from the sun's surface and extends over 16 million kilometers, it says in their study published on July 18th in the Astrophysical Journal.

The scientists knew something about the structure, or absence thereof, found within the corona. "Anyone who has seen a solar eclipse knows that the corona is not homogeneous in the way the Earth's atmosphere is: there are dense regions and sparsely populated areas everywhere," said Craig DeForest, a solar physicist at the Southwestern Research Institute Boulder, Colorado , [See Gorgeous Images of the Sun̵

7;s Corona in Simulations]

And these different densities are driven by the sun's magnetic field, he added. Beyond this low-resolution understanding, however, they remained in the dark.

Until now. "By looking at coronagraphs (ordinary cameras with visible light with special metal parts against direct sunlight) we can see individual structures in the corona," DeForest wrote in an e-mail to Live Science, based on the COR2 instrument on board NASA's STEREO-A spacecraft orbiting the sun between Earth and Venus.

One of the main reasons why DeForest and his colleagues observed the relatively fine details in the corona had to do with the advanced processing they used. The data – like those from the light of the background stars – were used to enhance the images create. And what they saw was a bit overwhelming.

Here's what they found: Once they got rid of the "noise", the team found structures inside the streamers of the corona – the streams of dense solar wind leaving the sun – which were just 12,500 miles (20,000 km) wide. "When we made the best measurements with the COR2 device to eliminate the noise, we found that every bright streamer is made up of innumerable smaller, fibrous strands," DeForest said. "These strands are the" structure "we talk about in the paper." [During Eclipses, Astronomers Try to Reveal the Secrets of the Solar Wind]

And DeForest said these "fibers" could be even smaller, so much so that the instrument could not resolve them.

They also found a lot of blobs, and yes, that's a technical word. It was coined in the 1990s by Neil Sheeley of the Naval Research Laboratory, who saw the relatively small clouds of charged gas and created time lapse films of the phenomenon.

"They are tiny (compared to the corona, but large) compared to the earth) of plasma released by the sun," DeForest said. "They are often enough that you can usually find at least some in a coronagraph movie, but seldom enough that they are usually only in one or two properties in the corona."

In this new study, he added, "We showed that the visible to date are just the big tail of a wide distribution of them." Blobs, puffs, and similar compact dense features are everywhere. "

Beyond some pretty research

"The outer part of the corona – the transition from the solar atmosphere to the solar wind that fills the interplanetary void – is almost the last unexplored part of our solar system," said DeForest. "Nobody really knows how the corona dissolves from the sun."

For example, the solar wind can rise deep in space in violent storms. But the scientists do not know what triggers this "turbulence" in the first place.

When the sun creates this turbulence, the resulting complex structures should be visible from the beginning on the journey of the solar wind. But so far, scientists have not had a keen eye on the corona to know one way or the other.

The new perspective could provide the answer. "What we found is that every bright streamer in the outer corona is made up of innumerable smaller, fiber-like strands down to sizes below a tenth of the smallest objects we've seen before," DeForest said. "This is interesting because it means that the outer corona is as strange and inhomogeneous as the inner corona, which in turn gives new insights into the great questions of solar physics as the solar wind is accelerated into emptiness."

The Parker Sun's probe, which will begin a seven-year mission this month, will delve even deeper into this mystery and others, including the fact that the solar corona is 300 times hotter than the lower atmosphere called the photosphere. [19659002] Original article from Live Science .


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