We present CH and CN index analysis and C and N abundance calculations based on the low-resolution blue spectra of red giant branch (RGB) stars in the Galactic globular cluster NGC 7089 (M 2). Our main goal is to investigate the C-N anticorrelation for this intermediate metallicity cluster. The data were collected with DOLORES, the multiobject, low

This work undertakes the study of the galaxy NGC 4861, using imaging centered at the strong lines H-alpha, H-beta, (O III) lambda 5007 and nearby continua. Integrated, absolute fluxes of 28 H II regions, and the region known as the bright knot, have been measured showing correlations between the equivalent width of H-beta and the excitation index

In this paper we present the Johnson-Cousins UBVR CCD photometry of the stars in King 2, an old open cluster towards the galactic anticenter. We have obtained the colour- magnitude diagram, the colour excess, the reddening, an estimate of the metallicity, and the distance modulus. The comparison of the observational colour- magnitude diagram with

The need of the GTC for acquisition cameras, wavefront sensors and scientific instrumentation operating in the optical wavelength range has led to the acquisition of various CCDs and CCD controllers. Due to stringent science, mechanical and ambient requirements the initial idea to employ a general purpose controller had been dropped in favor of two

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

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"