Ultraviolet Observations of Prominence Activation and Cool Loop Dynamics

Abstract

In this paper we investigate the thermal and dynamic properties of dynamic structures in and around a prominence channel observed on the limb on 2003 April 17. Observations were taken with the Solar and Heliospheric Observatory's Solar Ultraviolet Measurements of Emitted Radiation (SOHO SUMER) in lines formed at temperatures from 80,000 K to 1.6 MK. The instrument was pointed to a single location and took a series of 90 s exposures. Two-dimensional context was provided by the Transition Region and Coronal Explorer (TRACE) in the UV and EUV and the Kanzelhöhe Solar Observatory in Hα. Two dynamic features were studied in depth: an activated prominence and repeated motions in a loop near the prominence. We calculated three-dimensional geometries and trajectories, differential emission measures, and limits on the mass, pressure, average density, and kinetic and thermal energies. These observations provide important tests for models of dynamics in prominences and cool (~10⁵ K) loops, which will ultimately lead to a better understanding of the mechanism(s) leading to energy and mass flow in these solar features.