Intermediate-resolution spectroscopy in the range 625-775 nm is reported for a faint very-late-type object discovered in two CCD images taken near the center of the Alpha Per cluster. The spectrum shows strong absorption molecular bands, H-alpha emission, and KI absorption typical of late-M dwarfs; H-alpha varies conspicuously. The effective

The results of the 1989 Kaiko-Nankai diving cruise to the eastern Nankai accretionary wedge show that a narrow corridor on the top of a 2000 m deep ridge is characterized by concentrated surface manifestations of fluid seepage and chaotic outcrop orientations, suggesting active faulting along a right-lateral shear zone.Modern biological indicators

The results of one night of observations corresponding to an intensive site assessment campaign, held at the Observatorio del Roque de los Muchachos (La Palma) on July 22 1990, are presented and discussed. The goal of the campaign was to evaluate the contribution of free atmosphere, boundary layer, surface layer and dome + mirror seeing to image

Not Available

A photometric study of umbral bright features (umbral dots, clusters of umbral dots, bright grains of light bridges) in sunspots is presented. It is based on white-light images taken with a CCD video camera driven by an automatic image selection system. A direct linear relation between the observed brightness of the features and that of the

We report on intermediate-to-high resolution spectroscopy and standard broadband photometry of late-type visual companions to early-type stars. Our program stars are drawn from the sample of post-T-Tauri candidates studied by Lindroos (1986). Measurement of radial velocities and derivation of the surface abundances of lithium and heavier elements