Future telescopes can create similar maps to predict solar flares
The sun’s serene upper atmosphere, known as the corona, is an ever-changing plasma forest. However, mapping the strength of the magnetic fields that largely control this behavior has proven elusive. The fields are weak and the sun emits its crown.
Through observations made using a special instrument called a coronenggan to block the sun’s bright disk, solar physicists were able to measure the speed and intensity of waves plunging through coronary plasma (SN: 03/19 / 09). “This is the first time that we have harnessed the large-scale coronary magnetic field,” said Steven Tomczyk, a solar physicist at the High Altitude Observatory in Boulder, Colo., Who designed the coronograph.
In 2017, Tomczyk was part of a team using a total solar eclipse in North America to measure the corona’s magnetic field (SN: 8/16/17). He climbed a special camera in a Wyoming mountain range to capture polarized images of the crown like the crescent moon. (Went there, reporting on the team’s efforts to explain why the corona is hotter than the sun’s surface (SN: 8/21/17).) The team is looking at a small piece of the corona to test if a specific length of light can carry signatures of the magnetic field. It can be (SN: 08/21/18).
But it is the coronograph observations of 2016 that allow researchers to visualize the entire crown at once. Theorists showed decades ago that coronal wave velocities can be used to reduce the strength of the magnetic field. Such waves also help transport heat from the sun’s surface to the corona (SN: 11/14/19). But he has never measured the entire crown before.
The strength of the corona’s magnetic field is typically between 1 and 4 Gauss, several times stronger than the Earth’s magnetic field on the planet, Science researchers reported on August 7.
Creating a map is an important step, says the team. But what solar physicists want to do is continuously monitor the corona’s magnetic field at least once a day.
“The solar magnetic field is constantly changing,” said solar physicist Zihao Yang of Peking University in Beijing. Sometimes the sun emits explosive magnetic energy and sends plasma explosions into space (SN: 07/03/19). These ejections can destroy satellites or power grids if they hit Earth. Continuous monitoring of coronary magnetism will help predict these outbreaks. “Our work showed that we could use this technique to map the global distribution of the coronary magnetic field, but we only showed one map from a single set of data,” Yang said.
Measuring the strength of the corona’s magnetic field is “a big deal,” says solar physicist Jenna Samra of the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts. Getting better predictions of events in space, ”he said. This is a very good step in that direction. ”
Tomczyk and his colleagues are working on an updated version of the coronograph called COSMO for the Coronal Solar Magnetism Observatory that will use the same technique over and over again to predict the behavior of the sun.
“This is an important step for that,” said Tomczyk. “The point is to make it consistent, to do it all the time.”
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