Internal Structure of the 2019 April 2 CME

TL;DR

This study analyzes the internal structure of a CME near the Sun using data from PSP/WISPR, revealing detailed features like two loops within the flux rope that suggest complex internal configurations.

Contribution

First detailed internal CME structure analysis near the Sun using WISPR data, identifying two distinct flux rope loops with differing mass loading.

Findings

Identification of two linear features as flux rope loops

Bright loop indicates high mass loading

Dark loop appears mass-devoid

Abstract

We present the first analysis of internal coronal mass ejection (CME) structure observed very close to the Sun by the Wide-field Imager for Solar PRobe (WISPR) instrument on board Parker Solar Probe (PSP). The transient studied here is a CME observed during PSP's second perihelion passage on 2019 April 2, when PSP was only 40 R_sun from the Sun. The CME was also well observed from 1 au by the STEREO-A spacecraft, which tracks the event all the way from the Sun to 1 au. However, PSP/WISPR observes internal structure not apparent in the images from 1 au. In particular, two linear features are observed, one bright and one dark. We model these features as two loops within the CME flux rope channel. The loops can be interpreted as bundles of field lines, with the brightness of the bright loop indicative of lots of mass being loaded into those field lines, and with the dark loop being devoid of such mass loading. It is possible that these loops are actually representative of two independent flux rope structures within the overall CME outline.