Astronomers are always anxious to push their observations to the limit-basing results on objects at the detection threshold, spectral features barely stronger than the noise, or photometry in very crowded regions. In this paper we present a careful analysis of photometry in crowded regions and show how image blending affects the results and

Current models of the evolution of the known extrasolar planetary systems need to incorporate orbital migration and/or gravitational interactions among giant planets to explain the presence of large bodies close to their parent stars. These processes could also lead to planets being ingested by their parent stars, which would alter the relative

We explore the dependence of {T_eff}'s and colors of stellar models on the treatment of over-adiabatic convection, both in the atmosphere and in the interior. We compute main sequence, turnoff, and subgiant models for low metallicity stars (Z=2 10-4) using as boundary conditions two new sets of model atmospheres by the Wien group (Kupka \cite{kup96

Data recovered from the GOLF experiment on board the ESA/NASA SOHO spacecraft have been used to analyze the low-order low-degree solar velocity acoustic-mode spectrum below ν=1.5 mHz (i.e., 1

We present the results of a series of Chandra observations of globular cluster (GC) X-ray sources in M31. Among some 20 GC X-ray sources detected in our M31 observations, 2-3 of them show super-Eddington luminosity (> 1038 erg s-1). It is an interesting fact that the highest X-ray luminosities achieved by Galactic GCs are only several times 1037

IAUC 7617 available at Central Bureau for Astronomical Telegrams.