From the emission line map in Hα over the full face of the spiral galaxy NGC 3359, we analyze the internal velocity structure of the H II region population. The emission line profiles show central peaks, with turbulent velocity widths of

Primitive bodies (comets, Centaurs, trans-Neptunian objects, etc.) are the best-preserved remnants of the Solar Nebula. Their composition and structure harbor clues to the origin of solar and exosolar planets and the evolution of protoplanetary disks. The capabilities of the Gran Telescopio Canarias (GTC) and its instrumentation provide us a unique

We report here the first results of an extensive optical/near-infrared imaging and spectroscopic study of massive stellar clusters in Wolf-Rayet (WR) galaxies using observations obtained from KPNO (USA), OAN (Mexico), the HST and the 2MASS data archive. We have collected spectra, B-imagery and 2MASS JHK imagery of approximately 60 prominent stellar

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We present new spectroscopic observations of WC9 stars. As predicted by Williams & van der Hucht (2000), O II lines are weak in the dust-free star WR 88, which also shows a high ionization. Spectral variability is detected in WR 106 and WR 121. These findings are briefly discussed in terms of the conditions for dust formation in Wolf-Rayet winds.

We report on the in-orbit calibration of staring and chopped observations performed with the spectrophotometer ISOPHOT-S. Staring observations are calibrated using a Spectral Response Function which depends both on the signal and the elapsed observing time. Chopped observations are calibrated with a signal dependent Spectral Response Function