The OAS Project has been run with the support of the Spanish research funding agencies during the last dozen years . Within its framework, research on cultural astronomy has been developed for a s eries of ancient civilizations , from the Atlantic Islands to the Arabian Peninsula and beyond, with the Meditterranean Sea as the principal axis of

Se presenta un análisis arqueoastronómico de la orientación definida por los muros del santuario de entrada del oppidum ibérico Cerro de las Cabezas (Valdepeñas, Ciudad Real), situado en la Oretania septentrional, así como de otros recintos pertinentes para el análisis. El resultado más relevante es que dos de los muros perimetrales del santuario

New accurate and homogeneous optical UBVRI photometry has been obtained for variable stars in the Galactic globular cluster ω Cen (NGC 5139). We secured 8202 CCD images covering a time interval of 24 years and a sky area of 84 × 48 arcmin. The current data were complemented with data available in the literature and provided new, homogeneous

A current issue in the study of planetary nebulae with close binary central stars (CSs) is the extent to which the binaries affect the shaping of the nebulae. Recent studies have begun to show a high coincidence rate between nebulae with large-scale axial or point symmetries and close binary stars. In addition, combined binary-star and

We present high-resolution, time-resolved optical spectroscopy of the black hole X-ray transient Swift J1753.5-0127. Our optical spectra do not show features that we can associate with the companion star. However we do observe broad, double-peaked emission lines, typical of an accretion disc. We show that the mass of the compact object is likely >7

We investigated the reliability of our silicon atomic model and the influence of non-local thermodynamical equilibrium (NLTE) on the formation of neutral silicon (Si i) lines in the near-infrared (near-IR) H-band. We derived the differential Si abundances for 13 sample stars with high-resolution H-band spectra from the Apache Point Observatory