Hinode SOT Observations of Solar Quiescent Prominence Dynamics

Abstract

We report findings from multihour 0.2'' resolution movies of solar quiescent prominences (QPs) observed with the Solar Optical Telescope (SOT) on the Hinode satellite. The observations verify previous findings of filamentary downflows and vortices in QPs. SOT observations also verify large-scale transverse oscillations in QPs, with periods of 20-40 minutes and amplitudes of 2-5 Mm. The upward propagation speed of several waves is found to be ~10 km s-1, comparable to the sound speed of a 10,000 K plasma, implying that the waves are magnetoacoustic in origin. Most significantly, Hinode SOT observations reveal that dark, episodic upflows are common in QPs. The upflows are 170-700 km in width, exhibit turbulent flow, and rise with approximately constant speeds of ~20 km s-1 from the base of the prominence to heights of ~10-20 Mm. The upflows are visible in both the Ca II H-line and Hα bandpasses of SOT. The new flows are seen in about half of the QPs observed by SOT to date. The dark upflows resemble buoyant starting plumes in both their velocity profile and flow structure. We discuss thermal and magnetic mechanisms as possible causes of the plumes.