New Measures of STEREO CME Masses and Directions

Abstract Coronal mass ejections (CMEs) propagate away from the Sun throughout interplanetary space. The CME mass influences its evolution and interaction with the background solar wind; however, accurate CME masses are not routinely measured. We combine the CORSET catalog, which identifies CME regions in coronal images, with the standard mass estimation method based on excess brightness to create the first multiviewpoint catalog of CME masses. This catalog spans from 2007 through 2014 when both STEREO satellites were available for stereoscopic reconstructions. We determine a projected mass for each CORSET region, providing reconstructions at multiple times and perspectives for most CMEs. For a subset of events with paired CORSET STEREO A and B regions, we determine a deprojected CME mass and direction. Given a CME longitude, we can convert the projected mass to a “true” mass. By assuming the true mass should be the same from all viewpoints, we can combine the multiple perspectives to infer the “true” longitude, as done in R. C. Colaninno & A. Vourlidas. Additionally, we consider a revised technique where we assume the deprojected height and latitude should also be consistent from both perspectives. We compare our results with GCS CME reconstructions from LLAMACoRe and find our mostly automated deprojection techniques yield results comparable to those obtained through manual GCS reconstructions. The catalog contains over 35,000 masses corresponding to 1174 unique events in STEREO A, 688 in STEREO B, and 456 events with deprojected masses and directions.