Near-IR Spectroscopy of Blue Supergiants

Diffraction-limited observations with the E-ELT will make blue supergiants accessible to intermediate-resolution spectroscopy in galaxies out to the Virgo and Fornax clusters. BA-type supergiants (BA-SGs) will be primary targets for the study of the young stellar populations because of their enormous luminosities, their rich metal line spectra and their comparatively simple atmospheres. Quantitative analyses will allow stellar and galactochemical evolution to be investigated in different environments: in field galaxies, in galaxy groups and in clusters.