Solar prominences as a pre-eruptive state of CMEs

Oddbjorn Engvold

Abstract

The magnetic regions where solar prominences form and exist, the so-called filament channels, are invariably located above the narrow lanes between extended areas of opposite magnetic polarities in the photosphere. The main body of the dense prominence plasma is permeated by a generally horizontal, weakly helical magnetic field directed along the channel. Also, the magnetic fields in the chromosphere becomes horizontal and aligned close to the same path. Intimately connected with and spanning the the filament channel high above, are magnetic arcades which often are observed as hot coronal loops. The transition between the inner fields that run along the channel and the more transverse coronal arcades, is not well known. The notably reduced emission from the coronal cavity regions which surround many prominences inside the channels, prevents direct observations of the regions where this transition presumably may take place. The talk will review current observational results and ideas about the pre-eruptive state of the composite magnetic field structure of channels and their associated prominences. Recent findings of pre-eruptive observational signatures will be mentioned.
 

  Organization: Univeristy of Oslo
     Telephone: +47 22856521
           Fax: +47 22856505
        e-mail: oddbjorn.engvold@astro.uio.no
       Address: Institute of Theoretical Astrophysics
   University of Oslo
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   N-0315 Oslo, Norway