Helioseismic instruments aboard SOHO are making possible a more accurate way of investigating the internal structure of the Sun. Making use of the different techniques and characteristics of these instruments, it is possible to measure solar oscillations as variations of the photospheric velocity (GOLF, MDI) or as irradiance and radiance

This paper presents the first results obtained with the Jodrell Bank-IAC two-element 33-GHz interferometer. The instrument was designed to measure the level of the cosmic microwave background (CMB) fluctuations at angular scales of 1 deg-2 deg. The observations analysed here were taken in a strip of the sky at Dec.=+41 deg with an element

This article presents a theoretical framework for the evolution of the light-element nuclides in the Galactic disk. By understanding this evolution correctly, we can reliably obtain the primordial abundances of the nuclides D, 4He, and 7Li. We use two key assumptions, those of (1) infall of metal-poor gas to the disk at an increasing rate and (2)

El objetivo de esta tesis es el estudio de la historia de formación de nuestra Galaxia. Para ello, hemos analizado los sistemas estelares más viejos, los cúmulos globulares, obteniendo como resultado principal el que esa formación e produjo mediante un colapso rápido del halo. La tesis se presenta en tres bloques principales. -En el primero se

TeV gamma-ray signals from the Crab Nebula and Mkn 501 were detected with the HEGRA CT1 imaging Cerenkov telescope during periods when the moon was shining and during twilight. This was accomplished by lowering the high voltage supply of the photomultipliers in fixed steps up to 13%. No other adjustments were made and no filters were used. Laser

IAUC 7284 available at Central Bureau for Astronomical Telegrams.