Planetary alignment may dampen Sun magnetic activity

Planetary alignment may dampen Sun magnetic activity
by Robert Schreiber
Berlin, Germany (SPX) Aug 13, 2025

Our Sun appears to be unusually calm compared with other sunlike stars, showing magnetic activity levels about five times lower. Researchers at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) suggest that gravitational influences from planets in our solar system may be responsible. Over the past decade, the team has developed a model that attributes nearly all known solar activity cycles to tidal forces from planetary alignments. Their latest work also shows that this external synchronization naturally reduces the Sun's overall activity.

Currently, the Sun is at the peak of an approximately eleven-year activity cycle, producing more polar lights, solar storms, and space weather disturbances that can affect satellites and Earth's infrastructure. Even so, its strongest flares are 10 to 100 times weaker than those seen on comparable stars. This quiet behavior may be crucial for sustaining life on Earth, making it vital to understand its origin.

Solar activity displays numerous cycles, from hundreds of days to millennia. The HZDR model treats planets as "pacemakers"-particularly Venus, Earth, and Jupiter, whose combined tidal forces align every eleven years. These forces subtly boost the Sun's magnetic dynamo, interacting with the Sun's rosette-like orbital path to produce overlapping periodic fluctuations matching observations.

Lead researcher Frank Stefani notes that the model explains all identified solar cycles with surprising accuracy. In their latest findings, the team connects the Quasi Biennial Oscillation (QBO)-a roughly two-year fluctuation in solar activity-to their framework. QBO in this model not only matches an exact period but also suppresses overall solar activity.

While QBO has been observed with periods between 1.5 and 1.8 years, earlier studies linked it to Ground Level Enhancement events, where solar particles spike cosmic radiation at Earth's surface. Revisiting these events, the HZDR team found a dominant period of 1.724 years, nearly identical to the model's predicted 1.723 years, reinforcing the QBO link.

QBO overlays a shorter cycle on the Sun's eleven-year magnetic oscillation, preventing the magnetic field from staying at maximum strength for long. This creates two activity peaks-at maximum and during the QBO swing-reducing the average magnetic intensity. The resulting "bimodality" lowers the likelihood of extreme events like the 1859 Carrington storm, which caused auroras as far south as Rome and Havana and damaged telegraph systems.

Research Report:Adding Further Pieces to the Synchronization Puzzle: QBO, Bimodality, and Phase Jumps