The authors present long slit low dispersion flux calibrated spectra for the planetary nebula A 78, and from these they obtain the chemical abundances and their variation within the nebula. In the central part of the nebula almost no hydrogen is found implying that the envelope of the central star is burning helium. The authors also measured an

High-resolution VLA radio mapping at 1.46, 4.84, and 15.0 GHz is presented together with NIR J,H,K,L, and M mapping and photometry of a broad range of type I postmain-sequence nebulae. Many of these sources have extremely compact infrared and radio cores ranging from 0.1 to 0.01 pc in size; in some cases they contain up to 96 percent of the total

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The authors have obtained high-resolution spectrograms of H-rich central stars of planetary nebulae (CSPN) with the 3.6 m telescope and Cassegrain echelle spectrograph of the European Southern Observatory. They have determined the basic atmospheric parameters (Teff, log g, photospheric He abundance) for 22 of these CSPN, by fitting the observed

The galactic evolution of the abundances of the light-element isotopes (6Li, 7Li, 9Be, 10B, and 11B) is re-examined in view of recent measurements of the 7Li/6Li interstellar isotopic ratio. The high value of this ratio (≡40), found by Ferlet and Dennefeld (1984) towards ζ Oph, can be reproduced by simultaneously including contributions to the

U,B,V,R,I and simultaneous near infrared J,H,K light curves of the RS CVn system ER Vul are presented. A study of the mean levels compared to other years indicates that the system is highly variable, giving evidence that important changes occur over one month. Colours show an ultraviolet and infrared excess. There seems to be a contribution from a