The Double-Bubble CME of the 2020 December 14 Total Solar Eclipse

TL;DR

This study documents a rare double-bubble CME observed during the 2020 December 14 total solar eclipse, combining eclipse and space-based data to analyze its structure, evolution, and magnetic interactions in unprecedented detail.

Contribution

It provides the first detailed observation of a double-bubble CME structure from the solar surface to over 5 solar radii using eclipse data, linking multiple observational platforms.

Findings

Captured the full extent of a double-bubble CME during a total solar eclipse.

Linked prominence activity and active region interactions to the CME's structure.

Demonstrated eclipse observations' unique capability to contextualize space-based data.

Abstract

Total solar eclipses (TSEs) continue to provide an invaluable platform for exploring the magnetic topology of the solar corona and for studying dynamic events such as Coronal Mass Ejections (CMEs) -- with a higher spatial resolution over a larger spatially continuous extent than is possible to achieve with any other method at present. In this Letter, we present observations of the full extent of a `double-bubble' CME structure from the solar surface out to over 5 solar radii, as captured during the 2020 December 14 TSE. Its evolution through the corona was recorded from two observing sites separated by 13 minutes in their times of totality. The eclipse observations are complemented by a plethora of space-based observations including: Extreme Ultraviolet observations of the solar disk and low corona from SDO/AIA and STEREO-A/EUVI, white-light coronagraph observations from SOHO/LASCO-C2, radio from STEREO-A/WAVES and WIND/WAVES, and X-ray from GOES-16. We also characterize the magnetic field with a potential field source surface model. This CME event itself is of particular interest, as it demonstrates interactions between a prominence channel and an active region that led to the double-bubble structure. Despite the plethora of space-based observations, only the eclipse data are able to provide the proper context to connect these observations and yield a detailed study of this unique CME.