Observations are presented of high resolution interstellar Na I D and K I (lambda 7699 Angstroms) line profiles towards 7 stars in the globular cluster NGC 6541 and 3 field stars within 3° of the cluster. It is seen that the gas in this general direction (l, b ~ 350°, -11°) shows a complex structure, having the greatest number of components yet

We report the discovery of the optical counterpart to GRB 980326. Its rapid optical decay can be characterized by a power law with exponent - 2.10+/-0.13 and a constant underlying source at R_{{c}}=25.5+/-0.5 . Its optical colors 2.1 days after the burst imply a spectral slope of - 0.66+/-0.70 . The gamma -ray spectrum as observed with BATSE shows

We present the results of near-infrared H band (1.65 μm) imaging of 11 BL Lac objects with redshifts ranging from z = 0.05 to 0.9. We are able to clearly detect the host galaxy in seven low redshift (z

We have calculated a grid of empirically well tested evolutionary tracks with masses M between 0.5 and 50Msolar, spaced by approximately 0.1 in log M, and with metallicities Z=0.0001, 0.0003, 0.001, 0.004, 0.01, 0.02 and 0.03. We use a robust and fast evolution code with a self-adaptive non-Lagrangian mesh, which employs the mixing-length theory

Several options for the GTC (Gran Telescopio Canarias) installations have been evaluated. In particular, different dome types and distribution schemes for the support areas to be incorporated in the installation have been assessed. In order to select the dome type, a technical-economic study has been carried out, in which the most important

The purpose of this paper is to describe the Quality System that has been implemented in the Gran Telescopio Canarias (GTC) project to assure the quality of the GTC Telescope. This project is a high-tech scientific-engineering program and therefore it is important, as well as in other programs, that a common working methodology is set up among the