Analysis of Coronal Mass Ejections Observed by the Wide-field Imager (WISPR) on Parker Solar Probe

The Wide-field Imager for Solar Probe (WISPR) has provided high resolution images of multiple coronal mass ejections (CMEs) during its first seven encounters with the Sun. Here we present results of the analysis of the origin and trajectories of several of these CMEs with some unexpected results. WISPR has a wide fixed angular field-of-view (FOV), extending radially from 13.5° to 108° from the Sun and approximately 50° in the transverse direction, but the physical extent of the imaged coronal region varies directly with the distance of the spacecraft from the Sun. We have developed tools for determining the trajectories of solar eject which take into account the rapid spacecraft motion. The CMEs analyzed have also been observed by either STEREO A or LASCO or both. To relate and compare the CMEs seen in the WISPR images to simultaneous observation from another white light telescope, it is necessary to relate the fields-of-view of the telescopes at any given time to a common inertial frame of reference, e.g., the Heliocentric Inertial coordinate frame. Using World Coordinate System information in the images’ FITS headers, we project the trajectory determined from WISPR or features seen in the WISPR images onto images from the second white light telescope (or visa versa) to verify the trajectory determined from the WISPR data alone and to better understand the structure and evolution of the CMEs.