A FINE ABUNDANCE ANALYSIS OF 4 STARS IN THE ALPHA-PER CLUSTER - A CAUTIONARY TALE

High-resolution spectra of the F5 I b supergiant alpha Per and three d warfs belonging to the alpha Per cluster were obtained in order to sea rch for systematic differences in the abundances. Using LTE analyses o f the spectroscopic data we have found that [Fe/H] is about 0.3-0.5 de x smaller for alpha Per as compared to the dwarfs, which we ascribe pr imarily to non-LTE effects in the analysis of alpha Per. If this resul t is confirmed, then it will be necessary to correct LTE abundance ana lyses that have been performed on supergiants. Surprisingly, our estim ate for the mean value of [Fe/H] for the dwarfs is 0.17+/-0.06 dex; th is value is significantly larger than the accepted value for the clust er, about [Fe/H]=0.04. While we have not been able to determine the so urce of this discrepancy, there is some evidence that it is due to chr omospheric activity. (C) 1996 American Astronomical Society.