The solar system is constantly washed by a sea of charged particles that emanate from the Sun, and a research team spent 14 years chasing solar eclipses to learn more about this stellar spray.
The particles are called solar wind, and they come from the outermost region of the sun: the crown. If a person is lucky enough to observe a total solar eclipse, they will definitely see this pearly region surrounding the sun. This vaporous area has all the visual charm of a cosmic halo, but it is equally hell. The corona is the hottest region of the sun, reaching temperatures above 2 million degrees Fahrenheit (over 1 million degrees Celsius). The extreme temperature found in this gaseous stellar cocoon has intrigued scientists because it is a quite different story from what happens 1,600 kilometers below the corona, where the temperature is significantly cooler at 10,000 degrees F ( 5,500 degrees C), according to NASA.
Scientists want to understand the solar wind for many reasons. The solar wind defines the parameters of the solar system and sets its limits: Like the solar wind spreads thinner and thinner the further it is from the sun, the particles cannot resist the pushback from interstellar space. Much closer to Earth, the solar wind protects us from dangerous cosmic radiation but can also disrupt space communication satellites and GPS systems.
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Shaddia Habbal, solar researcher at the University of Hawaii, led a team in Oregon, Indonesia, Argentina, the Sahara Desert in Libya, the Gobi Desert in Mongolia, and many other sites in solar eclipse in the past 14 years. His goal was to observe the solar corona over a slightly longer period of time than it takes for the sun to complete a cycle of solar activity, approximately 11 years. Total solar eclipses, which occur when the moon’s disk blocks all sunlight except the corona, are a key opportunity for researchers to observe the source of the solar wind from Earth.
The team made high-resolution observations of 11 total solar eclipses using cameras fitted with specialized filters. This device allowed scientists to measure the temperatures of particles in the innermost part of the corona, which is the birthplace of the solar wind. The researchers then compared their results with data from NASA’s Advanced Composition Explorer (ACE) mission, launched in 1997 and observe the solar wind from a place in space located about 1/100 of the Earth-Sun distance.
During the sun’s 11-year cycle, the star oscillates between periods of dormancy and volatility. When the sun is calm, the star’s face shows few sunspots. This is quite different from the volatile season of the sun, when blemishes and solar flares are commonplace.
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The radically different appearance of the sun during the solar cycle left these scientists surprised to find that, despite all the global solar changes that occur over the course of 11 years, their 14 years of observations have shown no change in temperature. major for the inner crown. particles, which create the solar wind.
“Anything that heats the majority of the solar corona and wind is not very dependent on the activity cycle of the sun,” Benjamin Boe, a University of Hawaii solar researcher involved in the new research, said in a statement. . NASA statement which describes the study.
“The temperature at the sources of the solar wind in the corona is almost constant throughout a solar cycle,” Habbal said in the statement. “This discovery is unexpected because the coronal structures are driven by changes in the distribution of magnetized plasmas in the corona, which vary so much throughout the 11-year magnetic solar cycle.”
To solve this new mystery, the researchers plan to continue chasing total solar eclipses in the future for more observations, according to NASA. The next total solar eclipse will take place in December over Antarctica.
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