We investigate the structure in depth of a sunspot penumbra by means of the inversion code of the radiative transfer equation proposed by Ruiz Cobo & del Toro Iniesta (1992), applied to a set of filtergrams of a sunspot, scanning the Fe I line at 5576.1 A, with a sampling interval of 30 mA, from -120 to 120 mA from line center (data previously

IAUC 6104 available at Central Bureau for Astronomical Telegrams. IAUC 6104 available at Central Bureau for Astronomical Telegrams.

We confirm recent results about the differences in temperature and magnetic field strength between the umbra of large and small sunspots. Five Stokes I- and V-spectra from the darkest cores of three different umbrae have been analyzed with the inversion code of the radiative transfer equation by Ruiz Cobo & del Toro Iniesta (1992). The run with

Following our recent report of a strong Li lambda 6708 resonance line in the secondary of the black hole candidate V404 Cyg, we present here its detection in the quiescent spectrum of the neutron star binary Cen X-4. We obtain, via a spectral synthesis Local Thermodynamic Equilibrium (LTE) analysis, a surface lithium abundance in the K-type

We have analyzed long-slit spectroscopic data for a sample of 12 tidally disturbed elliptical galaxies. The spectra were obtained with the Kitt Peak National Observatory (KPNO) 4 m RC spectrograph. Rotation curves and velocity dispersion profiles have been measured at a variety of position angles in these galaxies and have been used to analyze the

EN LA PRIMERA PARTE DE LA TESIS SE ESTUDIA LA DINAMICA DE NEBULOSAS DE ANILLO INTERPRETADAS COMO UN PRODUCTO RESULTANTE DEL MATERIAL ESTELAR EYECTADO. SE DISCUTEN NUEVOS MODELOS HIDRODINAMICOS QUE PUEDEN EXPLICAR LA MAYORIA DE LAS CARACTERISTICAS QUE APARECEN EN LAS OBSERVACIONES DE LAS NEBULOSAS DE ANILLO. CON VISTAS A UNA PRIMERA APROXIMACION DE