Reconstructing the 3-D Trajectories of CMEs in the Inner Heliosphere

TL;DR

This paper presents a novel method for 3-D reconstruction of CME trajectories using STEREO data, revealing how CMEs accelerate or decelerate relative to the solar wind as they propagate through the inner heliosphere.

Contribution

The study introduces a new 3-D reconstruction technique for CMEs using STEREO data and demonstrates its effectiveness in analyzing CME kinematics in the inner heliosphere.

Findings

CMEs slower than solar wind are accelerated.

CMEs faster than solar wind are decelerated.

CME trajectories support a radial propagation model.

Abstract

A method for the full three-dimensional (3-D) reconstruction of the trajectories of coronal mass ejections (CMEs) using Solar TErrestrial RElations Observatory (STEREO) data is presented. Four CMEs that were simultaneously observed by the inner and outer coronagraphs (COR1 and 2) of the Ahead and Behind STEREO satellites were analysed. These observations were used to derive CME trajectories in 3-D out to ~15Rsun. The reconstructions using COR1/2 data support a radial propagation model. Assuming pseudo-radial propagation at large distances from the Sun (15-240Rsun), the CME positions were extrapolated into the Heliospheric Imager (HI) field-of-view. We estimated the CME velocities in the different fields-of-view. It was found that CMEs slower than the solar wind were accelerated, while CMEs faster than the solar wind were decelerated, with both tending to the solar wind velocity.