Not Available

The calculation of solar absolute fluxes in the near-UV is revisited, discussing in some detail recent updates in theoretical calculations of bound free opacity from metals. Modest changes in the abundances of elements such as Mg and iron-peak elements have a significant impact on atmospheric structure, and therefore self-consistent calculations

We report the discovery of a previously unseen X-ray source detected in a 5ks Chandra/ACIS observation starting on 2008-11-27.72 UT as part of our ongoing Chandra/HST M31 transient program. Its coordinates (subject to the standard boresight correction) are RA(J2000) 00:42:45.96, Dec(J2000) +41:10:36.60, with centroiding errors of 0.18" and 0.21"

We present an astrometric catalogue of positions and proper motions derived from the Carte du Ciel plates of the San Fernando zone, which has a mean epoch 1901.4 and a limiting magnitude V 15. Digitization has been made using a conventional flatbed scanner. Special techniques have been developed to handle the combination of plate material and the

The main goal of this work is to analyse new approaches to the study of the properties of astronomical sites. In particular, satellite data measuring aerosols have recently been proposed as a useful technique for site characterization and searching for new sites to host future very large telescopes. Nevertheless, these data need to be critically

APOGEE is a large-scale, NIR, high-resolution (R˜ 20 000) spectroscopic survey of Galactic stars. It is one of the four experiments in SDSS-III. Because APOGEE will observe in the H band, where the extinction is six times smaller than in V, it will be the first survey to pierce through Galactic dust and provide a vast, uniform database of chemical