We present a detailed model capable of explaining quantitatively the temperature fluctuations observed in luminous, large H II regions. The model is based on two assumptions which we justify on the basis of observations: that the major fraction of the hydrogen in the clouds that form the H II regions is not photoionized and is essentially H I, this

We present stellar parameters and metallicities for 29 planet-host stars, as well as for a large volume-limited sample of 53 stars not known to be orbited by any planetary-mass companion. These stars add to the results presented in our previous series of papers, providing two large and uniform samples of 119 planet-hosts and 94 “single” stars with

The hold-down, release and deployment mechanisms designed for SMOS PLM MIRAS have been a challenging activity in terms of design compromise, schedule and cost effectiveness. The existing design coming from previous phase was totally reanalysed to be adapted to a specific mission with extra requirements, making the previous design not totally valid

We present first measurements and the calibration procedure for the Polarimetric Littrow Spectrograph (POLIS) operated at the Vacuum Tower Telescope on Tenerife, together with a brief summary of the technical characteristics of the instrument. In its present configuration, we achieve a polarimetric accuracy of about 3 × 10-3 in the visible channel

We present high resolution spectroscopy of the common proper motion system FH Leo (components HD 96273 and BD+07 2411B), which has been classified as a novalike variable due to an outburst observed by Hipparcos, and we present and review the available photometry. We show from our spectra that neither star can possibly be a cataclysmic variable

New optical spectroscopy of the high-mass X-ray binary microquasar LS I +61 303 is presented. Eccentric orbital fits to our radial velocity measurements yield updated orbital parameters in good agreement with previous work. Our orbital solution indicates that the periastron passage occurs at radio phase 0.23 and the X-ray/radio outbursts are