On the detection of abundance stratifications in peculiar stars through the curve of growth method

Abstract

Theoretical curves of growth for manganese are computed for an atmosphere with T(eff) = 12,000 K and log g = 4. It is shown that the curves of growth may be strongly affected by the presence in the atmosphere of a plane parallel layer where manganese is overabundant. The theoretical results are compared with observations of the Hg-Mn star Nv Her. The existence of a radial inhomogeneity of manganese in the atmosphere of Nv Her is discussed in the framework of the diffusion processes.