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
P.O.Box 1029, Blindern
N-0315 Oslo, Norway