New Measurements of Plasma Properties near the Cusps of Pseudostreamers and Helmet Streamers

The role of magnetic topology in solar wind acceleration is an unsolved problem in solar physics. Coronal pseudostreamers differ from the more traditional helmet streamers in that they separate open-field lines of the same polarity rather than the opposite polarity. Helmet streamers and pseudostreamers are believed to be sources of slow to intermediate speed solar wind streams. Using multi-spacecraft and ground-based observations, we characterize the physical parameters of these coronal structures, and focus on their differences and similarities. Line-of-sight forward modeling (of a range of visible-light and UV emission diagnostics) is used to investigate how the differences in magnetic topology affect the plasma properties of the coronal structures and their wind. This work is supported by NASA grant NNX17AI27G to the Smithsonian Astrophysical Observatory.