[▲ The Sun’s Corona Loop (Credit: NASA / SDO) taken at a wavelength of 171 Å (= 17.1 nm) by the AIA equipment mounted on NASA’s solar observation satellite SDO]
The sun, seen in visible light, is usually expressionless and appears to have no features. However, when viewed at different wavelengths with a solar telescope, the sun is active and rich in character.One of them“Corona Loop”It is a huge arc-shaped radiation phenomenon called.
Corona loopBasic functions of the sunIs believed to be. Understanding how coronaloops are formed, changed, and moved is one of the key goals for understanding the Sun, the star closest to us.
Recently, regarding the corona loop, the solar physicistAnna MalanushenkoBy him and his collaboratorsInteresting research resultsWas announced.Some of the corona loopsNot what it looks likeIt says it may be.
Rather, the corona loops are written by the authors.“Corona Veil”Made by creases and wrinkles in a larger “sheet” of solar material, calledOptical illusionThere is a possibility that it is.
Since the first capture of the corona loop in the late 1960s, scientists have beenthree-dimensional structureI have made a hypothesis regarding what is going on.In the conventional model, the magnetic force formed by the lines of magnetic force of the sun“tube”Was thought to be.
The tube itself is invisible.What we see is bright flowing through the tube, like water flowing through a garden hose.Substances that make up the sun (plasma)is.this“Garden hose”The model fits well with known physics, and there was no reason to doubt it, at least initially. However, the observation results that did not match were accumulated.
![[▲ The corona loop of the sun taken at a wavelength of 335 Å (= 33.5 nm) by the AIA equipment mounted on NASA's solar observation satellite SDO. In this image, the loop does not spread much in the height direction and extends far from the surface of the sun. The earth is scaled to the bottom right (Credit: NASA / SDO)]](https://i0.wp.com/sorae.info/wp-content/uploads/2022/07/202207_picture4_4.jpg?resize=800%2C746&ssl=1)
[▲ The corona loop of the sun taken at a wavelength of 335 Å (= 33.5 nm) by the AIA equipment mounted on NASA’s solar observation satellite SDO. In this image, the loop does not spread much in the height direction and extends far from the surface of the sun. The earth is scaled to the bottom right (Credit: NASA / SDO)]
Just as the Earth’s air becomes thinner with altitude, the bright plasma of the Sun becomes thinner at higher altitudes. If the corona loop is a plasma tube, it should darken as the height increases.But many loopsConstant brightnessAnd there is no clear explanation for this.
Also, if the corona loop traces (traces) the traces of the sun’s magnetic force lines, the magnetic force lines spread throughout the space as you move away from the sun.The loop swellsmust. However, it doesn’t swell as much as it seems, and the reason is unclear.
I started to question the observationsMalanushenkoMr. Sun Corona“Optically thin”That is, it is translucent like fog or smoke and can occur in such an environment.Optical tricksI wanted to understand.
MalanushenkoOriginally heSolar flareWas used in the study of3D simulationI have created a program to reuse and “observe” it.See the real sun with a telescope2Just like shooting in dimension, the simulation was launched and the program shot a two-dimensional “image.” As a result, it was confirmed that an artificial corona loop was formed on the simulated sun, drawing a bright loop.
Moreover, unlike seeing the real sun, I was able to see the three-dimensional structure behind it.And she is a tube like a garden hoseObviously differentI found.
“This isn’t what you see on Earth, so I have no words how to express it,” she says. “This structure is a cloud of smoke, orVeilmosquito,Crumpled curtainI want to say that it looks like
[▲ An image of a simple comparison between the “Garden Horse” model (left) and the “Corona Veil” model (right) of the Corona Loop. The ball represents the sun, and the shadow on the wall is a two-dimensional image of the sun observed with a telescope (Credit: Anna Malanushenko)]
MalanushenkoTo explain how the veil causes the illusion of a corona loop, heSimple modelis created. The shadows on the walls represent the two-dimensional image we see with the solar telescope. The creases and wrinkles on the veil create a pattern of dark and light areas, similar to the image projected by a real tubular twisted thread.
“But many of the strands you see here are justProjection effectIt’s just that, it’s not real, “she adds.
Malanushenko and his collaborators have shown that not all corona loops are a visual illusion. Even in the simulation, there were many cases where a structure like a garden hose was actually formed.
NASA solar physicist and co-author of this treatiseJim Klimchuk“It would be exciting to say that all our ideas were wrong, and that there is a whole new paradigm,” he said. “But it is certain that such a veil exists, and now there are many veils or many loops.Ratio problemIt is. “
Corona veilJust found literallyHowever, it seems that the explanation of its formation is left to future research.
connection:The “rain” of plasma falling from the scorching sun corona loop
Source
Sentence / Tetsuro Yoshida
