On the Structure and Evolution of a Polar Crown Prominence/Filament System

Abstract

Polar crown prominences, that partially circle the Sun's poles between 60A degrees and 70A degrees latitude, are made of chromospheric plasma. We aim to diagnose the 3D dynamics of a polar crown prominence using high-cadence EUV images from the Solar Dynamics Observatory (SDO)/AIA at 304, 171, and 193 and the Ahead spacecraft of the Solar Terrestrial Relations Observatory (STEREO-A)/EUVI at 195 . Using time series across specific structures, we compare flows across the disk in 195 with the prominence dynamics seen on the limb. The densest prominence material forms vertical columns that are separated by many tens of Mm and connected by dynamic bridges of plasma that are clearly visible in 304/171 two-colour images. We also observe intermittent but repetitious flows with velocity 15 km s(-1) in the prominence that appear to be associated with EUV bright points on the solar disk. The boundary between the prominence and the overlying cavity appears as a sharp edge. We discuss the structure of the coronal cavity seen both above and around the prominence. SDO/HMI and GONG magnetograms are used to infer the underlying magnetic topology. The evolution and structure of the prominence with respect to the magnetic field seems to agree with the filament-linkage model.