8/26/2023-|Last update: 8/26/202311:04 PM (Mecca Time)
Although the solar wind is an essential feature of the sun, understanding how and where it is generated by the sun has proven elusive, and thus has been a major focus of study by scientists for decades.
And recently, a recent study – published in the “Science” journal – revealed that the “Solar Orbiter” spacecraft of the European Space Agency and NASA revealed a large number of tiny jets of material escaping from the sun’s outer atmosphere.
Each burst lasts between 20 to 100 seconds, and releases plasma at a speed of about 100 kilometers per second. These jets could be the source that feeds the solar wind, which scientists have long been waiting to find out.
The data came from the Ultraviolet Imager instrument on the solar orbiter (Shutterstock).
Ultraviolet imaging
The solar wind usually consists of charged particles known as plasma, which escape continuously from the sun, and spread outward through interplanetary space, colliding with anything in its path, and when the solar wind collides with the Earth’s magnetic field, it produces the aurora borealis.
Thanks to its superior instrumentation, the Solar Orbiter has taken an important step forward in understanding the source of the solar wind. The data came from the Extreme Ultraviolet Imager (EUI) instrument on the Solar Orbiter.
According to the press release published on the European Space Agency’s website on August 24, images of the sun’s south pole taken by the instrument on March 30, 2022 revealed a group of faint, short-lived features associated with small jets of plasma being expelled from the atmosphere. to the sun.
“We were only able to detect these tiny jets because of the unprecedented high-resolution, high-frequency images produced by the Ultrasound Imaging Instrument,” says Lakshmi Pradeep Chetta of the Max Planck Institute for Solar System Research in Germany, lead author of the paper describing this work. Ultraviolet”.
The instrument detected the solar plasma at one million degrees at wavelengths of 17.4 nanometers, and analysis of the images shows that the faint features revealed by the imaging are caused by the ejection of the plasma from the solar atmosphere.
The flow is intermittent and not always constant
Researchers have known for decades that much of the solar wind is associated with magnetic structures called coronal holes, which are regions where the magnetic field does not return to the sun but, instead, extends deep into the solar system, where plasma can flow along magnetic field lines. open, heading into the solar system, creating the solar wind. But the question was: “How is the plasma fired?”.
The traditional assumption was that because the corona is hot, it naturally expands and some of it escapes along magnetic field lines, but the new findings challenge the assumption that the solar wind is only produced as a result of the corona’s constant, steady flow.
Within the corona, there is a difference between solar flares with large energy, which is a billion times greater than what is called nanoflares. As for the small jets discovered by the solar tracker, they are less active than that.
These tiny jets exhibit about 1,000 times less energy than a nanoflare, and most of that energy goes into expelling the plasma. And the ubiquity of these small, faint jets indicates that they are expelling a large part of the matter that we see as the solar wind.
Commenting on what the new images revealed, David Bergmans of the Royal Observatory of Belgium and principal investigator of the Super Imaging Tool says, “It is an important step to find something on the disk that definitely contributes to the solar wind.”
As the mission continues, the solar orbiter will gradually adjust its orbit around the polar regions (ESA)
Further studies
At present, the Solar Orbiter is still orbiting the Sun near the equator, with the Superior Imager imaging across the South Pole.
As the mission continues, the spacecraft will gradually adjust its orbit around the polar regions. At the same time, activity on the Sun will advance during the current solar cycle and coronal holes will begin to appear at different latitudes, providing a unique new perspective.
So researchers will be keen to see what new they can gather about solar activity, a work of research that extends beyond the solar system.
The sun is the only star whose atmosphere we can closely monitor in such detail, and this will be reflected in understanding what is happening in other stars as well. This turns these observations into the discovery of a fundamental astrophysical process.
Source: websites + European Space Agency
