We examine the isotope production in star forming regions through a model of stellar-group population synthesis evolution. From this we obtain the light-curves of γ-ray line emission due to radioactive decay of 26Al, 60Fe and the e -e + annihilation line. We discuss in particular, the effects of the dispersion due to the discreteness of the stellar

Recently a number of works have given interesting results on the penumbral fine structure of sunpots (del Toro Iniesta, Bellot Rubio & Collados 2001; Schlichenmaier & Collados 2002), where, for instance, cold supersonic Evershed downflows were observed. In addition, there are recent results that show the existence of shock wave trains propagating

Metal opacity shapes the near-UV spectrum of late-type stars, which dominate intermediate and old stellar populations. Learning the details of how metal opacity blocks the light in this spectral region is of capital importance to understanding the energy balance in the atmosphere of these stars and, ultimately, building reliable models to interpret

An accurate determination of photospheric solar abundances requires detailed modeling of the solar granulation and accounting for departures from local thermodynamical equilibrium (LTE). We argue that the forbidden C I line at 8727 Å is largely immune to departures from LTE and can be realistically modeled using LTE radiative transfer in a time

In this article we present the results of more than 180 hours of time-series photometry on the low gravity (log g=5.4, Teff=29 300 K, log He/H=-3.0 by number) sdB pulsating star HS 2201+2610, obtained between September 2000 and August 2001. The temporal spectrum is resolved and shows 5 close frequencies: three main signals at 2860.94, 2824.10 and

Quantitative structural analysis of the galaxies present in the Hawaiian Deep Fields SSA13 and SSA22 is reported. The structural parameters of the galaxies have been obtained automatically by fitting a two-component model (Sérsic r1/n bulge and exponential disc) to the surface brightness of the galaxies. The galaxies were classified on the basis of