On the study of kinematics of eruptive quiescent prominences observed in He 304 Å
Abstract
The observations taken in He 304 Å by the EIT telescope aboard SoHO reveals that these images are extremely useful in tracing prominences because of the relatively sharper spine which is better visible in 304 Å than in H_α. We have developed a geometric technique of measuring the height of prominences. The technique was applied to six eruptive quiescent prominence images recorded by EIT in He 304 Å during January 2000-July 2003 in an attempt to identify the precursors of geo-effective caronal mass ejections (CMEs) that are associated with eruptive prominences. Our analyses show that prominence eruptions evolve through a pre-eruptive phase and an eruptive phase, which are characterized by lower velocities of several km s^{-1} and eruptive velocities of several tens to hundreds of km s^{-1}, respectively. The analyses also show that during the pre-eruptive phase, a prominence rises at a constant acceleration of several cm s^{-2} and not at constant velocity as reported by previous workers. We suggest that this phase is indicative of the precursor of prominence eruption. This might be useful in predicting the occurrence of an associated coronal mass ejection.
- Publication:
-
Bulletin of the Astronomical Society of India
- Pub Date:
- December 2007
- Bibcode:
- 2007BASI...35..447J
- Keywords:
-
- Sun: prominences;
- Sun: coronal mass ejections (CMEs);
- Sun: corona