Most of the spectra for the planet-host stars analyzed in this paper were studied in Papers I (Santos et al., 2000A&A...363..228S), II (Santos et al., 2001A&A...373.1019S), and III (Santos et al., 2003, Cat. . We refer the reader to these for a description of the data. During the last year, however, we have obtained spectra for 18 more planet host

With the 1 m Schmidt telescope of the Llano del Hato Observatory and the QUEST CCD camera, 380 deg2 of the sky have been surveyed for RR Lyrae variables in a band 2.3d wide in declination (centered at δ=-1°) and covering right ascensions from 4h1 to 6h1 and from 8h0 to 17h0. The bright limit (due to CCD saturation) and the faint limit are V~13.5

We discuss an ongoing study of the connection between galaxy merging/interaction and AGN activity, based on integral field spectroscopy. We focus on the search for AGN ionization in the central regions of mergers, previously not classified as AGNs. We present here the science case, the current status of the project, and plans for future

Near-infrared spectra were obtained for 117 red giants in the Fornax dwarf spheroidal galaxy with the FORS1 spectrograph on the VLT, in order to study the metallicity distribution of the stars and to lift the age-metallicity degeneracy of the red giant branch (RGB) in the color-magnitude diagram (CMD). Metallicities are derived from the equivalent

We have re-analyzed the Galactic O-star sample from citet{puls96} by means of line-blanketed NLTE model atmospheres in order to investigate the influence of line-blocking/blanketing on the derived parameters. The analysis has been carried out by fitting the photospheric and wind lines from H and He. In most cases we obtained a good fit, but we have

We present William Herschel Telescope (WHT) and Very Large Telescope (VLT) spectroscopy of MM Ser, the optical counterpart to Ser X-1. We deblend the red spectra of the two close stars identified by Wachter and show that the brighter of the two is responsible for the Hα and He I emission, hence confirming that this is the true counterpart of the X