Calibrated optical narrow-band imaging supplemented by near-infrared imaging of are Sh2-128 and Sh2-128N are presented. This region contains a developed H II region and a neighboring compact H II region associated with a pair of water maser sources. Midway between these the core of a CO cloud is located. Sh2-128 is an H II region at whose

We present high resolution UVES+VLT spectroscopic observations of 61 stars in the extended blue horizontal branches of the Galactic globular clusters NGC 1904 (M79), NGC 2808, NGC 6093 (M80), and NGC 7078 M15). Our data reveal for the first time the presence in NGC 1904 of a sizable population of fast (v sin(i) >= 20 km/s) horizontal branch (HB)

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We present an analysis over 3 different campaigns orientated to follow up the temporal spectra of the PNN NGC 246. Using wavelet analysis, we have found evidences of changes in time scale of hours. Such rapid changes have never been observed before. The temporal spectra of the 2001 dataset present a higher number of modulation frequencies and a

We present very fast radiative transfer tools of interest for the interpretation of future spectroscopic observations taken with the GTC and its post-focus instrumentation. Our radiative transfer codes are based on the iterative methods introduced by Trujillo Bueno & Fabiani Bendicho (1995). Taking into consideration spherical geometry and

OTELO is a survey of emission line objects that will be carried out using tunable filters with OSIRIS at the GTC. The survey will have a deep impact on extragalactic astronomy owing to its large area and its high sensitivity. In this paper we discuss quasar detection within this survey and estimate the number of quasars that can be found in OTELO.