Quantitative spectroscopy of supergiants

Norbert Przybilla
IfA

Blue supergiants are the visually brightest stars in galaxies.
Quantitative spectroscopy of these objects can now be performed at
distances well beyond the Local Group using large telescopes and modern
instrumentation. An overview is given on recent improvements in the NLTE
analysis techniques and their testing on high-resolution, high-S/N data of
objects in the Milky Way. First applications to supergiants in other Local
Group galaxies and beyond, in NGC300 and NGC3621, are outlined, indicating
a large potential for constraining massive star evolution, galactic
chemical evolution and the extragalactic distance scale.