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Observation of coronal loop torsional oscillation

T. V. Zaqarashvili
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Abstract

We suggest that the global torsional oscillation of solar coronal loop may be observed by the periodical variation of a spectral line width. The amplitude of the variation must be maximal at the velocity antinodes and minimal at the nodes of the torsional oscillation. Then the spectroscopic observation as a time series at different heights above the active region at the solar limb may allow to determine the period and wavelength of global torsional oscillation and consequently the Alfv{é}n speed in corona. From the analysis of early observation (Egan & Schneeberger \cite{egan}) we suggest the value of coronal Alfv{é}n speed as $\sim 500 {\rm km}{\cdot}{\rm s}^{-1}$.

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T. V. Zaqarashvili. 2003-01-16. Observation of coronal loop torsional oscillation. https://doi.org/10.1051/0004-6361%3A20030084

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