The kinematics and physical conditions of the bipolar planetary nebula M 2-48 are analysed from high and low dispersion long-slit spectra. Previous CCD narrow-band optical observations have suggested that this nebula is mainly formed by a pair of symmetric bow-shocks, an off-center semi-circular shell, and an internal bipolar structure. The bipolar

The heat flow and temperature structure within and surrounding a magnetic flux tube stored in mechanical equilibrium in a stellar convection zone are considered. The stationary thermal equilibrium state is determined through the analytical solution of a two-dimensional heat diffusion problem for an infinitely long cylinder with different thermal

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