In order to search for meridional circulation in the solar envelope, we have applied ring diagram analysis to a set of small regions over the surface. The helioseismic data consist of Solar Oscillation Investigation/Michelson Doppler Imager Dopplergrams taken over a time span of about 50 hr (~3000 images) on 1998 June 20-22. The regions studied

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The rationale for looking for prokaryote fossils in Martian materials is based on our present understanding of the environmental evolution of that planet in comparison to the history of the terrestrial environments and the development and evolution of life on Earth. On Earth we have clear, albeit indirect, evidence of life in 3.8 b.y.-old rocks

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We present high-resolution, near-infrared imaging of the circumnuclear region of the barred spiral galaxy M100 (NGC 4321), accompanied by near-infrared spectroscopy. We identify a total of 43 distinct regions in the K-band image, and determine magnitudes and colours for 41 of them. By comparison with other near-infrared maps we also derive colour

We present echelle spectroscopy in the 3500-10300 Å range of the Hourglass Nebula, which is embedded in the Galactic H II region M8. The data were obtained using the 2.1 m telescope at Observatorio Astronómico Nacional in San Pedro Mártir, Baja California. We have measured the intensities of 274 emission lines, in particular 88 permitted lines of C