A method to explore the column density of the Local Interstellar Medium (LISM) using absorptions in the resonance H and K lines of Mg II. The intrinsic strengths of these lines in the temperature and density conditions prevailing in warm clouds in the LISM allows them to be used to explore many lines of sight where lines such a NaD and Ca II H and

The general solution for the birth function B(m,t) of stars, derived by Casuso et al. (1989) was used to obtain a first-order analytical approximation to this function as a function of metallicity Z. This approximation was used to obtain a fit to the observational curve compiled by Tinsley (1980) for the cumulative function of stars with

An observational test of the binary hypothesis for the origin of the blue straggler (BS) stars has been performed searching for radial velocity variables among 27 BS in five galactic clusters. The significance of the BS phenomenon for the interpretation of evolutionary synthesis models and the spectra of elliptical galaxies is briefly discussed.

Given observed equivalent widths of Mg II and Mg I absorptions due to an interstellar cloud in which a late-B star is embedded, it is shown that the basic physical parameters (kinetic temperature, mean density, electron density, and radius) can be constrained. Hydrogen ionization by means of cosmic rays and the effect of the stellar radiation field

Results are presented for the sun's radial velocity in integrated sunlight. A resonant scattering spectrometer has been used to determine the frequencies and amplitudes of p-modes with spherical harmonics of degree (l) of less than 3, and a second spectrophotometer, which observes part of the sun by means of a spatial filter, has been used to

A CCD imaging survey of elliptical galaxies which present radio jets is described. The photometric and morphological properties of these galaxies and their nearby companions are described by Fourier analysis of the intensity variations along a set of elliptical contours fitted to the intensity distribution. A large fraction of the sample shows