SPECTROSCOPIC OBSERVATIONS OF AB SUPERGIANTS IN M33

We have observed 10 luminous blue stars in M 33 at intermediate disper sion and have determined spectral types and luminosity classes from th e blue and red spectrograms by comparing with galactic and SMC stars. H-alpha profiles have proved to be very useful in dissentangling lumin osity and metallicity effects, and constitute a valuable diagnostic wh en comparing spectral classifications in galaxies with different metal licities, We derive qualitative estimates of the stellar metallicities which range from solar to SMC-Like and an broadly consistent with abu ndance gradient results obtained for M 33 from H II region studies. Co mparison of the new data for B 324 with previous work shows that there is evidence for significant spectral variability strongly suggesting an LBV nature for this star.