We analyze the sample of measured nuclear magnitudes of the observed Jupiter Family comets (taken as those with orbital periods P < 20 years and Tisserand parameters T > 2) to derive sizes of comet nuclei, fraction of active surface areas, as well as to try to gain insight about their physical lifetimes and end states.

New evidence for a long thin Galactic bar (in contradistinction to the bulge), as well as for the existence of the ring and the truncation of the inner disc, are sought in the DENIS survey. First, we examine DENIS and Two Micron Galactic Survey star counts for the characteristic signatures of an in-plane bar and ring. The star counts in the plane

The highly convergent iterative methods developed by Trujillo Bueno and Fabiani Bendicho (1995) for radiative transfer (RT) applications are generalized to spherical symmetry with velocity fields. These RT methods are based on Jacobi, Gauss-Seidel (GS), and SOR iteration and they form the basis of a new NLTE multilevel transfer code for atomic and

This paper presents a brief overview of some recent advances in numerical radiative transfer, which may help the molecular astrophysics community to achieve new breakthroughs in the interpretation of spectro-(polarimetric) observations.

We present broadband photometry and provide a quantitative analysis of the structure of galaxies in the inner region of the Abell Cluster 2443 (z~0.1). The galaxy parameters have been derived by fitting a two-component model (Sérsic r1/n bulge and exponential disk) to a magnitude-limited sample. Using a new method of analysis that takes into

We present the photometric history of some luminous blue variable candidate stars of M 33. The search was made with the plates collection of the Bulgarian National Astronomical Observatory. We found that 1, of 6 objects studied, showe d photometric variations consistent with the LBV phase. These new data, together with the LBV type spectrum of the