A mysterious "heartbeat" of the sun has been the subject of research debates for years.
Now a research team has tracked down the phenomenon.
Newark - In addition to emitting light, the sun also has intense bursts of radio waves associated with solar flares, among other things.
In these radio waves, previous studies have detected signals with repeating patterns.
"These banging patterns are important for understanding how energy is released in these incredibly powerful explosions on the Sun and dissipated in the Sun's atmosphere," explains astronomer Sijie Yu of the New Jersey Institute of Technology (NJIT) in Newark.
But the origin of these repeating patterns, also known as quasi-periodic pulses (QPP), has long been a mystery to researchers.
Now a research group has apparently solved the mystery.
In a study published in the journal
Nature Communications
, a research team led by Yu and lead author Yuankun Kou describes where the "heartbeat"-like signals appear to be coming from.
Mysterious "heartbeat" of the sun: Study finds place of origin
With the help of the EOVSA radio telescope in California, the research group tracked down the mysterious phenomenon.
The telescope had observed a solar flare - a simple plasma magnetic field arc - on July 13, 2017.
The research group evaluated this data for their study and found a signal pattern that repeated every ten to 20 seconds - "like a heartbeat," explains lead author Kou.
The researchers found the strongest pulses in a 25,000 kilometer region of the sun that was in the center of the flare.
In this region, magnetic field lines meet, are interrupted and reconnect (reconnection).
This creates the tremendous energy that drives the solar flare.
"The repeating patterns are not unusual for solar radio outbursts," Kou notes.
But one discovery surprised the research team: there was a second source that the astronomers had not expected.
"Heartbeat" of the sun: Deeper insights into what is happening on the sun's surface
"The signals probably come from quasi-repetitive magnetic reconnections," explains Yu.
It is the first time that a quasi-periodic radio signal has been detected in the reconnection region.
The astronomer is pleased: "This discovery can help us to determine which of the two sources caused the other." According to the researchers, the new study provides deeper insights into the process that drives the numerous explosive events on the sun.
The sun is currently in a phase of increased activity.
The maximum of our star's current 11-year activity cycle is expected in 2024 or 2025.
However, as early as the beginning of 2023, there were solar storms that made the northern lights visible as far away as Germany.
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