Abstract

The determination of the chemical composition and distances of galaxies is crucial for constraining the theory of galaxy formation and evolution in a dark energy and cold dark matter dominated universe. However, the standard techniques to obtain information about the chemical composition and distances of star forming galaxies are subject to large systematic uncertainties which are poorly understood. As an alternative, I introduce a new method, which uses “supergiant stars”, the brightest stars in the universe, as individual sources of information about galaxies. I will present most recent results on the quantitative spectral analysis of such objects in galaxies beyond the Local Group based on medium and low resolution spectra obtained with the ESO VLT and the Keck telescopes on Mauna Kea. I will also discuss the perspectives of future work using the giant ground-based telescopes of the next generation such as the TMT on Mauna Kea and the European-ELT.