Experimental evidence for coronal mass ejection suppression in strong stellar magnetic fields

TL;DR

This study combines simulations and laboratory experiments to demonstrate that strong stellar magnetic fields can fully suppress coronal mass ejections, explaining their scarcity in observations.

Contribution

It provides the first laboratory-scale evidence that intense stellar magnetic fields can prevent CME formation and escape, supported by astrophysical simulations and plasma experiments.

Findings

Low-plasma beta CMEs are magnetically confined in 100 G stellar dipole fields.

Laser-driven plasma flows are halted by magnetic fields of 3e5 G, equivalent to 100 G stellar fields.

Flow disruption is caused by a kink instability in the plasma.

Abstract

Solar coronal mass ejections (CME) are routinely observed, but as of yet there exist few convincing detections of stellar CMEs. A reason for this could be the stronger magnetic fields of these stars, compared to that of our Sun, would prevent CME to form and escape. Here we combined astrophysical simulations, measurements of scaled high-energy laser-driven plasma flows, and 3D magneto-hydrodynamic modeling to test this hypothesis. Simulations show that in a 100 G stellar dipole field, low-plasma beta CMEs become magnetically confined. In the laboratory, a laser-produced plasma stream scaled to stellar CME conditions propagates freely at low applied magnetic fields (approximately 30 G stellar equivalent) but becomes unstable and halts entirely when the field is increased to 3e5 G (i.e., a 100 G equivalent). Numerical simulations suggest that the sudden disruption of the flow is induced by a kink instability. These results provide the first laboratory-scale evidence that strong stellar magnetic fields can fully suppress CME propagation, offering a physical explanation for their lack in stellar observations and highlighting the role of magnetic confinement in stellar evolution and exoplanet space weather.