Stellar flare research is an exciting and rapidly developing field of astrophysics. The Sun is an invaluable proving ground to test predictions of flare theories and to develop analytical techniques for future stellar applications, because the lack of spatial resolution for stellar flares pushes us to extrapolate models of solar flares to the

We report YALO consortium observation of a mini-outburst of Aquila X-1 = V1333 Aql, which occurred between July 04.27 and 07.29 UT. This X-ray binary outbursts approximately once per year, and most recently entered a mini-outburst during May 2000 (IAUC 7423,7429). We have been monitoring this source since April 5 in R using the YALO 1-m telescope

The study of the stellar content and physics of the ionized gas in local high-mass star-forming regions is specially important for better understanding extragalactic starbursts. Recent observations from space telescopes and near-infrared detectors have provided a wealth of new information about the gas and stars in these objects. In this paper, I

Realistic ab-initio 3D, radiative-hydrodynamical convection simulations of the solar granulation have been applied to Fe i and Fe ii line formation. In contrast to classical analyses based on hydrostatic 1D model atmospheres the procedure contains no adjustable free parameters but the treatment of the numerical viscosity in the construction of the

We limit the contribution of the hot intracluster gas, by means of the Sunyaev-Zeldovich effect, to the temperature anisotropies measured by the Tenerife experiment. The data are cross-correlated with maps generated from the ACO cluster catalog, the ROSAT PSPC catalog of clusters of galaxies, a catalog of superclusters and the HEAO 1 A-1 map of X

Various radial velocity surveys have now produced a number of candidates Very Low Mass Stars, Brown Dwarfs and Giant Extrasolar Planets to nearby G, K and M dwarfs. Building upon our experience in High Angular Resolution imaging, radial velocities measurements and atmosphere modeling, we discuss the detectability of Brown Dwarfs and Extrasolar