Search Publications
Validation of the new Hipparcos reduction
van Leeuwen, F.
Context: A new reduction of the astrometric data as produced by the Hipparcos mission has been published, claiming accuracies for nearly all stars brighter than magnitude Hp=8 to be better, by up to a factor 4, than in the original catalogue.
Aims: The new Hipparcos astrometric catalogue is checked for the quality of the data and the consisten…
The Geneva-Copenhagen survey of the Solar neighbourhood II. New uvby calibrations and rediscussion of stellar ages, the G dwarf problem, age-metallicity diagram, and heating mechanisms of the disk
Holmberg, J.; Nordström, B.; Andersen, J.
Context: Ages, metallicities, space velocities, and Galactic orbits of stars in the Solar neighbourhood are fundamental observational constraints on models of galactic disk evolution. Understanding and minimising systematic errors and sample selection biases in the data is crucial for their interpretation.
Aims: We aim to consolidate the calib…
A new calibration of Galactic Cepheid period-luminosity relations from B to K bands, and a comparison to LMC relations
Arriagada, P.; McArthur, B. E.; Benedict, G. F. +8 more
Context: The universality of the Cepheid period-luminosity (PL) relations has been under discussion since metallicity effects were assumed to play a role in the value of the intercept and, more recently, of the slope of these relations.
Aims: The goal of the present study is to calibrate the Galactic PL relations in various photometric bands (…
Oxygen abundances in nearby stars. Clues to the formation and evolution of the Galactic disk
Allende Prieto, C.; Lambert, D. L.; Ramírez, I.
The abundances of iron and oxygen are homogeneously determined in a sample of 523 nearby (d<150 pc) FGK disk and halo stars with metallicities in the range -1.5<[Fe/H]<0.5. Iron abundances were obtained from an LTE analysis of a large set of Fe I and Fe II lines with reliable atomic data. Oxygen abundances were inferred from a restricted …
Statistical properties of a sample of periodically variable B-type supergiants. Evidence for opacity-driven gravity-mode oscillations
Aerts, C.; Puls, J.; Lefever, K.
Aims:We have studied a sample of 28 periodically variable B-type supergiants selected from the HIPPARCOS mission and 12 comparison stars covering the whole B-type spectral range. Our goal is to test if their variability is compatible with opacity-driven non-radial oscillations.
Methods: We have used the NLTE atmosphere code FASTWIND to derive …
Eclipsing binaries observed with the WIRE satellite. II. β Aurigae and non-linear limb darkening in light curves
Southworth, J.; Bruntt, H.; Buzasi, D. L.
Aims:We present the most precise light curve ever obtained of a detached eclipsing binary star and use it investigate the inclusion of non-linear limb darkening laws in light curve models of eclipsing binaries. This light curve, of the bright eclipsing system β Aurigae, was obtained using the star tracker aboard the wire satellite and contains 30 …
Proper-motion binaries in the Hipparcos catalogue. Comparison with radial velocity data
Jorissen, A.; Frankowski, A.; Jancart, S.
Context: This paper is the last in a series devoted to the analysis of the binary content of the Hipparcos Catalogue.
Aims: The comparison of the proper motions constructed from positions spanning a short (Hipparcos) or long time (Tycho-2) makes it possible to uncover binaries with periods of the order of or somewhat larger than the short time…
Direct constraint on the distance of γ2 Velorum from AMBER/VLTI observations
Beckmann, U.; Marconi, A.; Testi, L. +99 more
Context: Interferometry can provide spatially resolved observations of massive star binary systems and their colliding winds, which thus far have been studied mostly with spatially unresolved observations.
Aims: We present the first AMBER/VLTI observations, taken at orbital phase 0.32, of the Wolf-Rayet and O (WR+O) star binary system
Long term photometric monitoring with the Mercator telescope. Frequencies and mode identification of variable O-B stars
Dupret, M. -A.; Uytterhoeven, K.; Drummond, R. +37 more
Aims: We selected a large sample of O-B stars that were considered as (candidate) slowly pulsating B, β Cep, and Maia stars after the analysis of their hipparcos data. We analysed our new seven passband geneva data collected for these stars during the first three years of scientific operations of the mercator telescope. We performed a frequency an…
The brightest stars of the σ Orionis cluster
Caballero, J. A.
Context: The very young σ Orionis cluster (~3 Ma) is a cornerstone in understanding the formation of stars and substellar objects down to planetary masses. However, its stellar population is far from being completely known.
Aims: This study's purpose is to identify and characterise the most massive stars of σ Orionis to complement current and …