1995A&A...295..459B

A method for the diagnostic of magnetic fields in Ap stars is presented. It is based on the joint interpretation of traditional circular polarization observations (giving B_l, the longitudinal magnetic field averaged over the stellar surface) and of broadband linear polarization observations. The method consists in a numerical, best-fit algorithm which takes into account the possibility of describing the time variation of broadband linear polarization by means of analytical expressions. The algorithm has been checked against numerical simulations and has shown to be reliable especially for the determination of the magnetic configuration of the star. Two applications have been considered for the stars HD 24712 and HD 71866 by interpreting new broadband linear polarization observations together with circular polarization data available in the literature.