We report new spectroscopic and photometric observations of the parent stars of the recently discovered transiting planets TrES-3 and TrES-4. A detailed abundance analysis based on high-resolution spectra yields [Fe/H] = -0.19 ± 0.08, T eff = 5650 ± 75 K, and log g = 4.4 ± 0.1 for TrES-3, and [Fe/H] = +0.14 ± 0.09, T eff = 6200 ± 75 K, and log g =

Using the Wide Field Imager (WFI) at the ESO 2.2 m telescope at La Silla and the CPAPIR camera at the CTIO 1.5 m telescope at Cerro Tololo, we have performed an extensive, multiband photometric survey of the open cluster IC 2391 (D~146 pc, age~50 Myr, solar metallicity). Here we present the results from our photometric survey and from a

We have analyzed the X-ray lightcurve of the star CI Cam, the optical counterpart of the X-ray transient XTE J0421+56 using data from XMM-Newton. Our motivation is based on evidence from ground based optical interferometry from the Keck and IOTA observatories which suggests that the dust surrounding CI CAM has a taurus morphology rather than a

Multi-object spectroscopic observations of A520 were carried out at the TNG telescope in December 2006. We used DOLORES/MOS with the LR-B Grism 1. As far as photometry is concerned, our observations were carried out with the Wide Field Camera (WFC), mounted at the prime focus of the 2.5m INT telescope (located at Roque de los Muchachos observatory

Empleando imagenes adquiridas con la cámara de alta resolución ACS (Advanced Camera Survey) del Telescopio Espacial Hubble (HST), hemos hecho un cartografiado de la emisión en Halpha en las galaxias M51 y NGC 4449, encontrando y analizando una pobación completo de regiones HII. Para las regiones HII de ambas galaxias analizamos la función de