The discovery of lithium in the spectrum of the binary system V404 Cygni is described. A high lithium abundance in the secondary star, close to that of very young stars, is derived. Without lithium production, the secondary would have to be comparable in age to the Pleiades cluster. If the system is not being seen at an early moment in its lifetime

Spectroscopy and mapping of the type I postmain-sequence source CRL 618, taken with the 45-m antenna of the Nobeyama Radio Observatory and the 12-m NRAO facility at Kitty Peak, are presented. It is shown that the exterior constant velocity envelope has a typical aspect ratio of about 0.8, extends over a range not less than 70 arcsec, and has an

We present the results of a spectroscopic analysis of 25 galactic luminous OB stars. The gravities are in general lower than previously assumed, especially for giants. The helium abundances are also higher than normal in many cases. Using data from the spectroscopic analysis, radii, luminosities and masses are derived. The observed wind terminal

Profiles of the Na I D doublet in three bright features (clusters of umbral dots), located in a relatively dark umbra, were analyzed by means of the 'local two-component modeling' to obtain the 'true' continuum intensities and temperatures of the bright features and their dark surroundings (background). The intensities of two central and one

Results of a program of near-IR monitoring of a sample of blazars and miniblazars observed during 1990 and 1991 with the Carlos Sanchez Telescope, in Teide Observatory, Tenerife are presented. All of the objects in the sample show blazar activity during the course of the observations. Several of the objects in the sample have been monitored for

CCD narrow-band H-alpha photometry of the Sextans A Local Group dwarf irregular galaxy is presented. Fourteen H II regions have been recorded. Their identification charts, H-alpha luminosities and sizes are given, and their luminosity and size distributions are discussed. Twenty-five stars with masses between 15 and 30 solar masses, distributed