Science & technology

40 Years of Data Reveals Sun's Interior During Quiet Phases

Will solar oscillations revolutionize space weather forecasting or expose flaws in our understanding of stars?

Published MAR 5

40 Years of Data Reveals Sun's Interior During Quiet Phases

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Above: NASA/SDO timelapse shows a sunspot on the sun, on Feb. 14, 2011. Image credit: NASA/Solar Dynamics Observatory/Getty Images

The Facts

Researchers from the University of Birmingham and Yale University analyzed over 40 years of data from the Birmingham Solar-Oscillations Network to study the sun's internal structure during four successive solar cycle minima, spanning from the end of cycle 21 to the beginning of cycle 25.
arXiv
PHYS
The study, published in Monthly Notices of the Royal Astronomical Society, used helioseismology, which examines tiny vibrations inside the sun formed by trapped sound waves, to infer changes below the sun's surface. These sound waves make the sun oscillate at about three thousandths of a cycle per second, roughly one oscillation every five minutes.
PHYS
GB News
The solar minimum between cycles 23 and 24, occurring in 2008-09, was the deepest and longest on record. During this period, the helium ionization zone signature was significantly larger and the sound speed in the sun's outer layers was slightly higher compared to the other three minima studied.
arXiv
PHYS
The findings suggest that lower magnetic flux levels during the 2008-09 minimum resulted in higher gas pressure, higher temperatures and higher sound speed in the sun's outer layers. These structural differences were marginally significant but detectable through helioseismic analysis.
GB News
arXiv
Observing the sun's behavior during quiet periods helps characterize how activity levels develop in subsequent cycles. Solar activity produces space weather, which can cause radio blackouts, GPS errors, power grid disruptions and damage to communications satellites.
PHYS
GB News
The Times (UK)
The techniques used in this study could be applied to other sun-like stars through upcoming missions such as the European Space Agency's PLATO. This would potentially help scientists understand how stellar activity changes and influences local environments, including any planets these stars may host.
PHYS
The Times (UK)

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The Spin

Narrative A

Tracking the sun's hidden musical "notes" during quiet periods could revolutionize space weather forecasting and protect critical infrastructure. Scientists discovered that subtle shifts in solar oscillations reveal internal changes that directly influence dangerous solar eruptions. These insights could help safeguard Earth and orbital assets from solar storms that disrupt satellites, power grids and communications.

John Peters on X

GB News

Narrative B

Forty years of helioseismic data reveal persistent discrepancies between solar models and observations, especially during quiet phases, challenging the precision of some assumptions in stellar physics. While the sun's overall structure is well-constrained, these gaps show that refinements are still needed in modeling stellar interiors and in drawing conclusions about space-weather impacts and forecasting.

Frontiers

Metaculus Prediction

Editor's Note

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