In a surprising discovery, scientists have detected aurora-like emissions in the sun’s atmosphere.
At an altitude of about 40,000 kilometers (25,000 miles), a sunspot is rapidly growing inside the Sun. light sphereA team of astronomers led by Sijie Yu of the New Jersey Institute of Technology has recorded a type of long-lasting radio emission never seen before.
The sun emits all kinds of radiation when it’s active, which the researchers say is similar to the aurora borealis.
“We detected a unique type of long-lasting polarized radio burst that emanates from the sunspot and lasts for more than a week.” Yuu says.
“This is quite different from the typical ephemeral solar radio bursts, which usually last minutes to hours. This is an exciting discovery that has the potential to change our understanding of magnetic processes in stars.”
The glowing, rippling Northern Lights are one of the most spectacular sights on Earth, but although their shapes vary greatly, they are not unique to our home planet. Auroras have been detected on all the major planets of the solar system and even on Jupiter’s four Galilean moons.
They are formed when solar particles are caught in magnetic field lines, which act as accelerators that amplify the energy of the particles before they are deposited, usually in the atmosphere, and the particles interact with the atoms and molecules within them. Creates shine. Here on Earth, we can see that sparkle dancing in the sky.
However, visible light is only part of the aurora’s emission spectrum.There is radio components, too. And although the Sun emits large amounts of radio radiation through other processes, such as bursts of radio activity, the radiation floating above the sunspots had a profile similar to that of a radio aurora.
This has interesting implications. Sunspots are temporarily dark, cool regions on the Sun’s surface, or photosphere, caused by regions of unusually strong magnetic fields. limit solar plasma. And nowhere in the solar system are solar particles more abundant than in the sun itself.
Therefore, it stands to reason that magnetic field acceleration of solar particles could occur there. It is much more powerful than Earth because of the much stronger solar magnetic field.
excellent To tell The team’s spatially and temporally resolved analysis suggests that [the emissions] This is due to electron cyclotron maser (ECM) emission with high-energy electrons confined within a converging magnetic field shape. ”
“The cold, highly magnetic regions of sunspots provide a favorable environment for ECM radiation to occur. This is analogous to the magnetic polar caps of planets and other stars, and provides localized opportunities for studying these phenomena. “It could provide a similar solar analogue,” she says.
![](https://www.sciencealert.com/images/2023/11/sunspot-aurora-diagram.jpg)
In fact, it’s not uncommon for stars to emit auroral radio signals. A few years ago, a team of scientists identified a large number of stars emitting nondescript radio waves and linked this to the presence of closely orbiting exoplanets, whose atmospheres could be sucked into the stars, creating auroras. I thought that a release was occurring.
The planets in our solar system are too far away from the sun to have a similar effect, but we are close enough to the sun to see weaker auroral-type emissions that we would miss in distant stars. .
The researchers believe that flare activity in a region not far from the sunspot injects high-energy electrons into the magnetic field loops rooted in the sunspot, creating what the researchers call a “sunspot radio aurora.” I believe that This is some of the clearest evidence to date of the mechanisms involved and suggests new ways to study the magnetic activity of stars and the behavior of star points in distant stars.
The research team plans to examine archival data to see if they can find evidence of auroras in past bursts of solar activity.
“We are beginning to piece together the puzzle of how energetic particles and magnetic fields interact in systems with long-lived star points.” says solar physicist Surajit Mondal. “They exist not only in our sun, but also in stars far beyond our solar system,” the New Jersey Institute of Technology professor said.
This study natural astronomy.