Impulsive brightenings/velocity transients in quiescent solar prominences

✍ Scribed by G. D. Toot; J. M. Malville

• Publisher: Springer
• Year: 1987
• Tongue: English
• Weight: 833 KB
• Volume: 112
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00148488

✦ Synopsis

In some quiescent prominences, areas are found where the Ha emission profiles are centrally reversed. By combining good spatial, spectral, and temporal resolution, the detailed behavior of these reversal regions has been investigated. Many of the regions show a growth and subsequent decay in the affected area, peak intensity, line width, and depth of the central reversal. Lifetimes of the time-varying reversal features range from 10 to more than 60 min, and they are found near the edges of the prominence fine structure. These events are similar to the impulsive events that the authors discussed in an earlier paper, and may share a common cause. The detailed behavior of the Ha line profiles is consistent with these reversal features being true self-reversal of the line, indicating unusually high column masses in these areas. Some models of condensation of coronal material to the prominence state predict temporary regions of high density, perhaps high enough to produce the observed reversal. This implies that reversal features are the result of on-going condensation of coronal material into already formed prominences, a result which impacts models of prominence formation and stability.