We present the first results of CaII triplet observations from VLT/FLAMES for Sculptor, Fornax and Sextans dSphs. For each galaxy, we obtained accurate velocity and metallicity measurements for hundreds of stars out to and beyond the tidal radius. In each case, we find clear evidence for the presence of two distinct stellar components with

In this work we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. Three-dimensional (3D) spectra and maps of Mrk 231 clearly show that the BAL systems I and II are extended (reaching 1.2--1.3 kpc, from the nucleus) and elongated at the position angle (PA) close

The variation of some fundamental constants of nature is a prediction of several unifying theories. As physics at recombination is sensitive to the value of the electron mass and the fine structure constant, cosmic microwave background radiation (CMB) provides an excellent laboratory to constrain such theories. In this work, we used WMAP-3yr data

In this paper we review the current situation regarding the study of the metallicity-giant planet connection. We show that planet-host stars are more metal-rich than average field dwarfs, a trend that remains after the discovery of now more than about 100 planets. Current results also point out that the planetary frequency is rising as a function

We present results of photometric observations of the high-amplitude EC 14026-type star, Balloon 090100001. The data were obtained in broad-band B filter and span over five weeks, consisting of about 150 hours of observations. Fourier analysis of these data led us to the detection of at least 50 modes of pulsation, out of which 37 are independent

The advantages of using a telescope of large aperture, like the GTC, for mid-infrared imaging are demonstrated. Examples are given to compare the characteristics of the images in the 8 to 13 μ m regime recently taken with the 2.1 m telescope at San Pedro Mártir with those obtained with a 10 meter class telescope. Finally, 10μ m images of the BN/KL