An experiment that recreates coronal mass ejections in the lab

Amazing stuff!

"Some of the most iconic images of the Sun have captured the explosive force of coronal mass ejections (CMEs), in which huge clouds of magnetized plasma erupt from the solar atmosphere. But CMEs have only rarely been sighted on other stars, a discrepancy that has puzzled astrophysicists for many years.

Now an international research team has devised an experiment that recreates these stellar eruptions in the lab, providing clear evidence that CMEs can be suppressed by strong magnetic fields. The same experimental approach could also be used to investigate the role that magnetic confinement plays in other stellar activity. ..."

"... The current study ... combines astrophysical simulations, high-energy laser-plasma experiments, and advanced 3D plasma numerical modelling. The results show that strong magnetic fields of active stars can completely suppress CMEs before they escape into space. “The unique combination of theory, laboratory tests, and numerical simulations provides the first experimental evidence supporting a long-standing prediction that stellar magnetic fields can confine these large-scale eruptions.” ..."

From the abstract:

"Solar coronal mass ejections (CMEs) are routinely observed, but as of yet there exist few convincing detections of stellar CMEs. A reason for this could be that 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 magnetohydrodynamic modeling to test this hypothesis.

Simulations show that, in a 100 G stellar dipole field, low-plasma 𝛽 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 3 ×105  G  (i.e., a 100 G equivalent).

Analytical estimates and numerical simulations suggest that the sudden disruption of the flow is induced by a kink instability. Even though the laboratory environment does not fully reproduce the complex magnetic flux-rope topology of CMEs, 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."

Physics - Lab-Based Plasmas Shed Light on Stellar Mystery "Using high-power lasers to drive highly magnetized plasmas, researchers have probed the stellar processes that control coronal mass ejections."

Stellar eruptions in the laboratory: First experimental evidence for their suppression in strong magnetic fields (original news release)

Experimental Evidence for Coronal Mass Ejection Suppression in Strong Stellar Magnetic Fields (no public access)

Experimental evidence for coronal mass ejection suppression in strong stellar magnetic fields (preprint, open access)

Computer simulation of a coronal mass ejection for a star (green) with a strong magnetic field (lines). The eruption is confined by the magnetic field and thus does not escape the star.