New high-resolution, high-sensitivity Westerbork Synthesis Radio Telescope Hi synthesis observations of the spiral galaxy NGC 3631 are presented. In the total atomic hydrogen map, the spiral arms are well distinguished from the interarm regions, while the sensitivity allows detection of Hi in all but a few isolated regions of the areas between the

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Aluminous mare basalts are the dominant lithology at the Luna 16 landing site in Mare Fecunditatis. For trace element analysis by micro-INAA techniques, we selected 23 of the 52 Luna 16 basaltic soil fragments studied by Kurat et al. (1976) and used a microcoring technique to extract microgram-sized samples from grain mount thin sections

The preservation of the excellent image quality of the 'Roque de los Muchachos' Observatory (ORM) is one of the most important design criteria for the enclosure of the future large telescope. Additionally, the cost of a large telescope and its instrumentation is so high that it would be regrettable if its own enclosure deteriorates the telescope

We obtained K-band (2.0--2.5 mu m) infrared spectra of the visually obscured superluminal source GRS 1915+105 at three different epochs of 1995, at times when it was detected as a hard X-ray source. The three spectra exhibit H I Br gamma (2.167 mu m) and He I (2.058 mu m) emission lines. The spectral morphology, absolute magnitude, and time

Light curves of the very low-mass member of the alpha Persei open cluster, AP J0323+4853, obtained during two different observing runs in 1994 and 1995, display a starspot rotational modulation of period ~7.6h. With a most likely mass of 0.09 Msolar, close to the substellar limit, AP J0323+4853 is the lowest mass star so far for which a photometric