CCD spectroscopy of SMC supergiants

The equivalent widths of the stellar features of a sample of SMC supergiants have been measured from CCD spectra obtained in the blue wavelength region with the ESO 3.6-m telescope at a dispersion of 29 A mm-1. A comparison of these measurements with those for their galactic counterparts shows that the SMC members have generally weak metal lines. No weakness is detected in the SMC members' helium lines. The present observations confirm that the diffuse interstellar 4430 A band is present in the SMC. Its strength relative to E(B-V) is significantly weaker than in our Galaxy. (author)