The Magnetic Structure of Solar Prominence Cavities: New Observational Signature Revealed by Coronal Magnetometry

TL;DR

This study uses coronal magnetometry to reveal a characteristic magnetic polarization signature in solar prominence cavities, supporting the flux-rope model and its implications for solar eruptions.

Contribution

First observational detection of a 'lagomorphic' polarization signature in prominence cavities, linking it to magnetic flux-rope structures.

Findings

Identification of a 'lagomorphic' polarization pattern in cavities.

Evidence supporting flux-rope magnetic topology in prominences.

Correlation between polarization signatures and velocity patterns.

Abstract

The Coronal Multi-channel Polarimeter (CoMP) obtains daily full-Sun above-the-limb coronal observations in linear polarization, allowing for the first time a diagnostic of the coronal magnetic field direction in quiescent prominence cavities. We find that these cavities consistently possess a characteristic "lagomorphic" signature in linear polarization indicating twist or shear extending up into the cavity above the neutral line. We demonstrate that such a signature may be explained by a magnetic flux-rope model, a topology with implications for solar eruptions. We find corroborating evidence for a flux rope structure in the pattern of concentric rings within cavities seen in CoMP line-of-sight velocity.