As a part of a project devoted to the study of the Ursa Minor dwarf spheroidal (dSph) galaxy, the star formation history of the galaxy is presented. The analysis uses wide-field photometry, encompassing about 1°×1° (the total covered area being 0.75 deg2), which samples the galaxy out to its tidal radius. Derivation of the star formation history

The properties of solar photospheric inter-network fields are studied using observations from the Advanced Stokes Polarimeter. By averaging over large areas of the observed map we are able to bring down the noise level to approximately 10-5 and determine typical magnetic properties of granules and intergranular lanes outside the magnetic network.

Our Galaxy seems to own, in addition with the oblate outer bulge (see poster of Picaud, Chereul and Robin) a longer and thiner in-plane bar (Lopez Carredoira, 2001). We compared stars counts and color-magnitude diagrams from the Besancon Model simulations (without this bar) with stars counts from observations at the Teide Observatory (near infrared

We have investigated the dynamical interaction of low- and intermediate-mass stars (from 1 to 5 Msolar) with their interstellar medium (ISM). In this first paper, we examine the structures generated by the stellar winds during the asymptotic giant branch (AGB) phase using a numerical code and the wind history predicted by stellar evolution. The

With a sample of 17 delta Scuti stars belonging to 5 young open clusters, we study correlations between fundamental parameters and the oscillation amplitude. The results published in a paper recently accepted by A and A show a significant correlation between the parameter i´(estimation of the angle of inclination of the star) and the oscillation

We present high-resolution Very Large Telescope/Ultraviolet Visual Echelle Spectrograph observations of 56 stars in the extended horizontal-branch (EHB) of the Galactic globular clusters NGC 1904, NGC 2808, NGC 6093, and NGC 7078. Our data reveal for the first time the presence in NGC 1904 of a sizable population of fast (vsini>=20 km s-1)