Search Publications
Star counts in the Galaxy. Simulating from very deep to very shallow photometric surveys with the TRILEGAL code
Hatziminaoglou, E.; Girardi, L.; Groenewegen, M. A. T. +1 more
We describe TRILEGAL, a new populations synthesis code for simulating the stellar photometry of any Galaxy field. The code attempts to improve upon several technical aspects of star count models, by: dealing with very complete input libraries of evolutionary tracks; using a stellar spectral library to simulate the photometry in virtually any broad…
Astrophysical parameters of Galactic open clusters
Scholz, R. -D.; Piskunov, A. E.; Kharchenko, N. V. +2 more
We present a catalogue of astrophysical data for 520 Galactic open clusters. These are the clusters for which at least three most probable members (18 on average) could be identified in the ASCC-2.5, a catalogue of stars based on the Tycho-2 observations from the Hipparcos mission. We applied homogeneous methods and algorithms to determine angular…
Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters
Luri, X.; Jorissen, A.; Turon, C. +4 more
The availability of the Hipparcos Catalogue has triggered many kinematic and dynamical studies of the solar neighbourhood. Nevertheless, those studies generally lacked the third component of the space velocities, i.e., the radial velocities. This work presents the kinematic analysis of 5952 K and 739 M giants in the solar neighbourhood which inclu…
Eclipsing binaries as standard candles. HD 23642 and the distance to the Pleiades
Maxted, P. F. L.; Southworth, J.; Smalley, B.
We present a reanalysis of the light curves of HD 23642, a detached eclipsing binary star in the Pleiades open cluster, with emphasis on a detailed error analysis. We compare the masses and radii of the two stars to predictions of stellar evolutionary models and find that the metal and helium abundances of the Pleiades are approximately solar. We …
The primordial binary population. I. A near-infrared adaptive optics search for close visual companions to A star members of Scorpius OB2
Kaper, L.; Brown, A. G. A.; Zinnecker, H. +2 more
We present the results of a near-infrared adaptive optics survey with the aim to detect close companions to Hipparcos members in the three subgroups of the nearby OB association Sco OB2: Upper Scorpius (US), Upper Centaurus Lupus (UCL) and Lower Centaurus Crux (LCC). We have targeted 199 A-type and late B-type stars in the KS band, and …
Abundance trends in kinematical groups of the Milky Way's disk
Soubiran, C.; Girard, P.
We have compiled a large catalogue of metallicities and abundance ratios from the literature in order to investigate abundance trends of several alpha and iron peak elements in the thin disk and the thick disk of the Galaxy. The catalogue includes 743 stars with abundances of Fe, O, Mg, Ca, Ti, Si, Na, Ni and Al in the metallicity range -1.30 <…
The lithium content of the Galactic Halo stars
Primas, F.; Charbonnel, C.
Thanks to the accurate determination of the baryon density of the universe by the recent cosmic microwave background experiments, updated predictions of the standard model of Big Bang nucleosynthesis now yield the initial abundance of the primordial light elements with unprecedented precision. In the case of ^7Li, the CMB+SBBN value is significant…
Astrometric orbits of SB^9 stars
Babusiaux, C.; Jorissen, A.; Pourbaix, D. +1 more
Hipparcos Intermediate Astrometric Data (IAD) have been used to derive astrometric orbital elements for spectroscopic binaries from the newly released Ninth Catalogue of Spectroscopic Binary Orbits (SB^9). This endeavour is justified by the fact that (i) the astrometric orbital motion is often difficult to detect without the prior knowl…
Chemical abundances in 43 metal-poor stars
Magain, P.; Gustafsson, B.; Asplund, M. +3 more
We have derived abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni, and Ba for 43 metal-poor field stars in the solar neighbourhood, most of them subgiants or turn-off-point stars with iron abundances [Fe/H] ranging from -0.4 to -3.0. About half of this sample has not been spectroscopically analysed in detail before. Effective temperatures…
The mass loss of C-rich giants
Bergeat, J.; Chevallier, L.
The mass loss rates, expansion velocities and dust-to-gas density ratios from millimetric observations of 119 carbon-rich giants are compared, as functions of stellar parameters, to the predictions of recent hydrodynamical models. Distances and luminosities previously estimated from HIPPARCOS data, masses from pulsations and C/O abundance ratios f…