Effects of Coronal Mass Ejections on Distant Coronal Streamers

TL;DR

This study investigates how a large coronal mass ejection influences distant solar coronal streamers, revealing that magnetic field changes, rather than shocks or waves, cause streamer bending.

Contribution

It provides evidence that magnetic field alterations from a moving magnetic rope, not shocks or waves, explain streamer behavior during CMEs.

Findings

Streamer bending correlates with magnetic field changes.

No conclusive evidence for shock or wave explanations.

Magnetic field dynamics drive streamer responses.

Abstract

The effects of a large coronal mass ejection (CME) on a solar coronal streamer located roughly 90 degrees from the main direction of the CME propagation observed on January 2, 2012 by the SOHO/LASCO coronagraph are analyzed. Radial coronal streamers undergo some bending when CMEs pass through the corona, even at large angular distances from the streamers. The phenomenon resembles a bending wave traveling along the streamer. Some researchers interpret these phenomena as the effects of traveling shocks generated by rapid CMEs, while others suggest they are waves excited inside the streamers by external impacts. The analysis presented here did not find convincing arguments in favor of either of these interpretations. It is concluded that the streamer behavior results from the effect of the magnetic field of a moving magnetic rope associated with the coronal ejection. The motion of the large-scale magnetic rope away from the Sun changes the surrounding magnetic field lines in the corona, and these changes resemble the half-period of a wave running along the streamer.