Context. Several works have found an increase of the abundances of the s-process neutron-capture elements in the youngest Galactic stellar populations. These trends provide important constraints on stellar and Galactic evolution and they need to be confirmed with large and statistically significant samples of stars spanning wide age and distance

On the basis of Synthetic Horizontal Branches computed with Sweigart and Gross (1976) Horizontal Branch evolutionary tracks, and by means of Sweigart and Gross (1978) Red Giant Branch star models, the calibration of the ratio R = N(HB)/N(RGB) in terms of helium abundance (Y), He-core mass (Mc) and Horizontal Branch morphology is derived. The

Aims: For more than 1.5 years we spectroscopically monitored the star KELT-6 (BD+31 2447), which is known to host the transiting hot-Saturn KELT-6 b, because a previously observed long-term trend in radial velocity time series suggested that there is an outer companion. Methods: We collected a total of 93 new spectra with the HARPS-N and TRES

Aims: Stellar activity is the ultimate source of radial-velocity (hereinafter RV) noise in the search for Earth-mass planets orbiting late-type main-sequence stars. We analyse the performance of four different indicators and the chromospheric index log R'HK in detecting RV variations induced by stellar activity in 15 slowly rotating (υ sin i ≤ 5 km

Detailed line profiles from the nebular gas surrounding the radio galaxy 3C 227 are presented. High-resolution spectroscopy around [O iii] 4959- and 5007-A emission lines, with an unprecedentedly high signal-to-noise ratio, reveals broad and asymmetric line profiles all across the nebulae. The average width of the line complex is of the order of

The relative bar torques for 45 galaxies observed at K-band with the 4.2 m William Herschel Telescope are determined by transforming the light distributions into potentials and deriving the maximum ratios of the tangential forces relative to the radial forces. The results are combined with the bar torques for 30 other galaxies determined from our