The spectra of O and B supergiants (Sgs) are known to be affected by a significant form of extra line broadening (usually referred to as macroturbulence) in addition to that produced by stellar rotation. Recent analyses of high-resolution spectra have shown that the interpretation of this line broadening as a consequence of large-scale turbulent

Context. The fundamental properties of brown dwarfs evolve with age. Models describing the evolution of luminosities and effective temperatures, among other physical parameters, can be empirically constrained using brown dwarfs of various masses in star clusters of well-determined age and metallicity. Aims: We aim to carry out a spectroscopic and

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The goals of the S4G project are described by Sheth et al. (2010, submitted). (1 data file).

Spitzer Space Telescope Infrared Array Camera imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6 μm band, which is