A new empirical calibration of the (B-V) index versus the three fundamental stellar parameters T(eff), (Fe/H), and log g is presented whose range of validity is adequate to analyze the main sequence and turnoff regions of most of the stellar cluster systems. Significant systematic differences are found between this new calibration and previous ones

High resolution, high S/N spectra obtained using RETICON and CCD detectors are used to determine the abundances of Al, Si, Ca, Ni and Fe in 23 disc stars in the metallicity range -1.2 ⪉ [Fe/H] ⪉ +0.3. The authors have found overabundances, with respect to iron for Al (≡0.4), Si (≡0.3), and Ca (≡0.2) in stars between -1.2 ⪉ [Fe/H] ⪉ -0.5. The

IAUC 4663 available at Central Bureau for Astronomical Telegrams. IAUC 4663 available at Central Bureau for Astronomical Telegrams.

EL PRESENTE TRABAJO SE HAYA DIVIDIDO EN DOS PARTES CLARAMENTE DIFERENCIALES AUNQUE ESTRECHAMENTE RELACIONADAS. EN LA PRIMERA SE DESARROLLA UN CONJUNTO DE PARAMETROS CAPACES DE CARACTERIZAR ESTRUCTURAS PRESENTES EN LOS PERFILES FOTOMETRICOS ACIMUTALES DE GALAXIAS, APLICANDOLOS A LA ESTRUCTURA ESPIRAL DE LAS GALAXIAS NGC 1832 Y NGC 7479 EN LAS BANDAS

The authors have determined the masses and orbital parameters for the galaxies in the strongly interacting binary NGC 4782/4783 by finding a numerical simulation of the collision that accurately represents all of the observed properties of the system. With this simulation, the authors have completely determined the three-dimensional orientation and

EL DESARROLLO DE LA HELIOSISMOLOGIA SE HA BASADO EN TECNICAS ESPECTROMETRICAS, MIDIENDO LA VARIACION DE LA VELOCIDAD SUPERFICIAL DEL SOL. A TRAVES DEL ESTUDIO DE LOS MODOS ACUSTICOS SOLARES PERO MEDIDOS COMO VARIACIONES EN LA LUMINOSIDAD SE PUEDE OBTENER UNA INFORMACION COMPLEMENTARIA DE GRAN IMPORTANCIA ASI COMO MEJORAR LAS TECNICAS FOTOMETRICAS