SE HAN REALIZADO OBSERVACIONES ESPECTROSCOPICAS CON RESOLUCION ESPACIAL Y RESOLUCION ESPECTRAL INTERMEDIA PARA UNA MUESTRA DE NEBULOSAS PLANETARIAS (NP) EXTENSAS REPRESENTATIVAS DE DIFERENTES CLASES. SE HAN INCLUIDO NP CON MULTIPLES CAPAS (M 1-46, NGC 2438, NGC 5882 Y NGC 6720), BIPOLARES (K 4-55, M 1-75, NGC 2440 Y NGC 2818) Y DEFICITARIAS EN

We present the results of Thuan & Gunn r CCD imaging observations of the Universidad Complutense de Madrid (UCM) sample of emission-line galaxies (ELGs), selected by the presence of Hα emission in low-resolution objective prism spectra. In this work we characterize photometrically and morphologically a total of 212 objects from the UCM survey. This

This thesis is made of three main parts. In the first one a sample of 55 galaxies with an active nucleus (Seyfert 1, Seyfert2 and LINERs) is analysed; these were observed with the 4.2m WHT and 1m JKT in CCD narrow band H-alpha +[NII] and [OIII] to map the distribution of HII regions and the morphology of the circumnuclear extended emission

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We present LTE and NLTE results on the formation of LiI lines (λ6103, λ6708, and λ8126) in the atmospheres of solar metallicity dwarfs with effective temperatures in the range 5500K to 2000K. NLTE effects are governed by overionization of Li and by the interlocking effects of energy levels. For stars with T_eff_>=4000K, we confirm previous findings