Determination of the complete vector magnetic field in solar prominences, using the Hanle effect
Résumé
Various methods which are liable to provide the three components of the prominence magnetic field are investigated. It is noted that the methods consist in adding information supplementary to that which results from the Hanle effect analysis of linear polarization measurements of an emission line. This supplementary information can be (1) the linear polarization measurements of another line (which is thought to be the most reliable method), (2) the projection of the field direction onto the plane of the sky; or (3) the longitudinal field derived from Zeeman effect measurements. It is noted that all these methods lead to two magnetic field solutions. The way in which the varying scattering geometry due to the sun's rotation makes it possible to choose between them is described.