We describe a set of Hα emission line profiles from populations of H II regions in nearby spiral galaxies. These are characterized by a strong Gaussian central peak, and lower intensity higher velocity wing features. From the peak we extract a non-thermal velocity component, due to the internal turbulence of the region. The plot of the widths of

We present new observations of IRAS 04000+5052, a Galactic H II region that is associated with a young stellar cluster and is possibly located in the Perseus arm. We have found that contrary to previous claims, this object is not a compact metal-poor H II region. The electron density and chemical composition of the nebula are similar to those of

Since the beginning of precise Doppler surveys, which have had stunning success in detecting extrasolar planetary companions, one surprising enigma has emerged: the relative paucity of spectroscopic binaries where the secondary mass lies in between the stellar and planetary mass regime. This gap in the mass function for close-in (a

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We present here the results of astrometric, photometric and spectroscopic observations leading to the determination of the orbit and dynamical masses of the binary L dwarf 2MASSW J0746425+2000321. High angular resolution observations spread over almost 4 years and obtained with the Hubble Space Telescope (HST), the ESO Very Large Telescope (VLT)

The Large Magellanic Cloud (LMC) has a unique cluster formation history in that nearly all of its globular clusters were formed either ~13 Gyr ago or less than ~3 Gyr ago. It is not clear what physical mechanism is responsible for the most recent cluster formation episode and thus the mysterious age gap between the LMC clusters. We first present