We present the results of applying a new chemo-evolutionary stellar population model, developed in a previous paper, to new high-quality observational data of the nuclear regions of two representative elliptical galaxies and the bulge of the Sombrero galaxy. Here we fit in detail ~20 absorption lines and six optical and near-infrared colors

We study deformations of the standard embedding of the Lie algebra $Vect(S^1)$ of smooth vector fields on the circle, into the Lie algebra of functions on the cotangent bundle $T^*S^1$ (with respect to the Poisson bracket). We consider two analogous but different problems: (a) formal deformations of the standard embedding of $Vect(S^1)$ into the

We present new BV photometry for 6564 stars in the field of the globular cluster NGC 6366, using a wide field CCD camera at the prime focus of the Isaac Newton Telescope (INT 2.5m). The mean internal accuracy of the present V magnitudes and (B-V) colours ranges from 0.005mag for the stars at the top of the Red Giant Branch to 0.07mag for the

We have obtained near-infrared observations of some of the faintest objects so far known towards the Pleiades young stellar cluster, with the purpose of investigating the sequence that connects cluster very low-mass stars with substellar objects. We find that infrared data combined with optical magnitudes are a useful tool to discriminate cluster

A survey of interstellar Na I D1 and D2 absorption features found in the spectra of 31 early-type stars in the first and fourth Galactic quadrants reveals a new picture of the large-scale kinematics of interstellar gas in the vicinity of the Sun. While absorption features found in the spectra of stars in the fourth Galactic quadrant show the gas

BP Tau is one of the few classical T Tauri stars for which the presence of a hot spot in the surface has been reported without ambiguity. The most likely source of heating is gravitational energy released by the accreting material as it shocks with the stellar surface. This energy is expected to be radiated mainly at UV wavelengths. In this work we