The code that we are developing for the empirical modelling of LBVs using the Sobolev approximation ] for the line transfer, yields accurate results that compare well with those obtained using the co-moving frame method. By including absorption by the continuum in the resonance region in addition to escape from the resonance region we get a much more accurate result for the hydrogen ground level population. The following properties make the code extremely fast:•
the Sobolev approximation for the line transfer
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the choice of the local approximate lambda operator A*, which yields the exact local contributions to the continuum radiation field
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the method of preconditioning the set of statistical equilibrium equations, which makes computationally expensive linearization unnecessary.
This means that the code is ideally suited for empirical modelling, in the sense that one can iteratively fit an atmospheric model to the observations.