Based on the Sérsic parameters, obtained by fitting pixel to pixel their deep optical galaxy images, the structural properties of the underlying stellar host of a sample of 20 star-forming dwarf galaxies have been analyzed. Our 2D technique has been improved to derive reliable Sérsic models, such as the proper isolation of the starburst emission

The partition function for atoms in a gas with partial ionization is obtained by assuming that the internal and atomic linear energy densities are equal, and considering that the kinetic energy per degree of freedom is sufficient to ionize the upper levels of the atoms, and, at the same time, approximating the sum by an integral, which we solve

Our photometric observations of 18 mainbelt binary systems in more than one apparition revealed a strikingly high number of 15 having positively re-observed mutual events in the return apparitions. Our simulations of the survey showed that the data strongly suggest that poles of mutual orbits between components of binary asteroids are not

The point spread function of a segmented aperture is seriously affected by the misalignment of the segments. Stringent requirements apply to position sensors and their calibration. The Active Phasing Experiment (APE) will be a technical instrument aimed at testing possible phasing techniques for a European Giant Optical Telescope (EGOT) in a

Barred galaxies represent more than 2/3 among disk galaxies. The evolution of barred galaxies is deeply influenced by the dynamics of the bar. Moreover, the evolution of the bar itself determines the morphology of the rest of the galaxy. In this work, and by means of numerical simulations, we will show the evolution of isolated barred galaxies from

In this paper the approximate Lambda-Operator (ALO) developed by Olson, Auer and Buchler (OAB, 1986) is inspected from a more mathematical standpoint and compared to presently most commonly applied ALOs. For simple model calculations,it is shown that OAB's operator which contains no arbitrary parameter always works close to the optimum convergence