The beat and bump mass discrepancies have been a long standing, unsolved difficulty in the Cepheid modelling (Cox 1980). The new opacities of Rogers & Iglesias (1992) has provided a partial solution to the problem, bringing the beat masses into good agreement with other mass determinations (Moskalik, Buchler & Marom 1992; herafter MBM). The discrepancy for the bump masses has also been greatly reduced, nevertheless it has not been eliminated entirely.
Recently, the new version of the Livermore tables has been released (Iglesias, Rogers & Wilson 1992). The new calculations take into account previously disregarded spin-orbit coupling in the iron atoms. The inclusion of this effect leeds to a further enhancement of the “metal opacity bump” around 2-5xl05K. In the following we repeat the calculations of MBM to assess the consequences of this enhancement for the bump mass calibration.