Trajectory Determination for Coronal Ejecta Observed by WISPR/Parker Solar Probe

TL;DR

This paper introduces a new method for determining the 3D trajectories of coronal mass ejections observed by WISPR on the Parker Solar Probe, validated through comparison with other white-light imaging instruments.

Contribution

The paper presents a novel technique for 3D trajectory determination of CMEs using WISPR data, incorporating a curve-fitting approach and validation with multiple viewpoints.

Findings

Successfully determined CME trajectories with the new method.

Validated the technique by comparing with LASCO/C3 and STEREO-A/HI1 observations.

Estimated uncertainties in trajectory parameters.

Abstract

The {\it Wide-field Imager for Solar Probe} (WISPR) on {\it Parker Solar Probe} (PSP), observing in white light, has a fixed angular field of view, extending from 13.5$^{\circ}$ to 108$^{\circ}$ from the Sun and approximately 50$^{\circ}$ in the transverse directions. Because of the highly elliptical orbit of PSP, the physical extent of the imaged coronal region varies directly as the distance from the Sun, requiring new techniques for analysis of the motions of observed density features. Here, we present a technique for determining the 3D trajectory of CMEs and other coronal ejecta moving radially at a constant velocity by first tracking the motion in a sequence of images and then applying a curve-fitting procedure to determine the trajectory parameters (distance vs. time, velocity, longitude and latitude). To validate the technique, we have determined the trajectory of two CMEs observed by WISPR that were also observed by another white-light imager, either LASCO/C3 or STEREO-A/HI1. The second viewpoint was used to verify the trajectory results from this new technique and help determine its uncertainty.