We propose to use GMOS-N in MOS mode to obtain metallicities for roughly 100 red giant stars in the nearby (770 kpc) dwarf galaxy LGS 3. We have obtained deep imaging of LGS 3 with the Hubble Space Telescope Advanced Camera for Surveys, creating color-magnitude diagrams (CMDs) reaching roughly a magnitude below the oldest main-sequence turnoff with

We construct rest-frame luminosity functions (LFs) at 3.6, 4.5, 5.8, 8 and 24 μm over the redshift range 0 z 2 for galaxies and 0 z 4 for optical quasi-stellar objects (QSOs), using optical and infrared (IR) data from the Spitzer Wide-area Infrared Extragalactic (SWIRE) Survey. The 3.6- and 4.5-μm galaxy LFs show evidence for moderate positive

Helioseismology is able to study the solar interior through the observation of the solar oscillation modes propagating inside the Sun. Pressure-driven modes (p modes) provide a very detailed picture of the external convective zone above 0.7 R[&sun;]and the radiative zone down to ~0.2 R[&sun;] where only a few of such modes penetrate so far. To

Aims.We conduct an intensive study of the rich, X-ray luminous, and hot galaxy cluster Abell 697 (at z=0.282), likely containing a diffuse radio-emission, to determine its dynamical status. Methods: .Our analysis is based on new spectroscopic data obtained at the TNG telescope for 93 galaxies and on new photometric data obtained at the INT

Beginning in 2001, the Gemini Observatory began the development of an innovative and aggressive education and outreach program at its Southern Hemisphere site in northern Chile. A principal focus of this effort is centered on local education and outreach to communities surrounding the observatory and its base facility in La Serena Chile. Programs

We carried out optical and Hα photometry of two contact binaries (V861 Herculis, EQ Tauri). The light curve modeling revealed stellar spots in both contact systems and strong Hα excess in the position of the observed stellar spots. A correlation was found between the V-R and R-Hα colour indices of V861 Her.