Search Publications
The Besançon Galaxy model renewed. I. Constraints on the local star formation history from Tycho data
Luri, X.; Figueras, F.; Haywood, M. +2 more
Context. The understanding of Galaxy evolution can be facilitated by the use of population synthesis models, which allows us to test hypotheses on the star formation history, star evolution, and chemical and dynamical evolution of the Galaxy.
Aims: The new version of the Besançon Galaxy model (BGM) aims to provide a more flexible and powerful…
An edge-on translucent dust disk around the nearest AGB star, L2 Puppis. VLT/NACO spectro-imaging from 1.04 to 4.05 µm and VLTI interferometry
Kervella, P.; Chiavassa, A.; Chesneau, O. +6 more
As the nearest known AGB star (d = 64 pc) and one of the brightest (mK ≈ -2), L2 Pup is a particularly interesting benchmark object to monitor the final stages of stellar evolution. We report new serendipitous imaging observations of this star with the VLT/NACO adaptive optics system in twelve narrow-band filters covering the…
A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun. I. Atmospheric parameters and color similarity to the Sun
Porto de Mello, G. F.; da Silva, R.; da Silva, L. +1 more
Context. Solar twins and analogs are fundamental in the characterization of the Sun's place in the context of stellar measurements, as they are in understanding how typical the solar properties are in its neighborhood. They are also important for representing sunlight observable in the night sky for diverse photometric and spectroscopic tasks, bes…
Joint astrometric solution of HIPPARCOS and Gaia. A recipe for the Hundred Thousand Proper Motions project
Michalik, Daniel; Lindegren, Lennart; Hobbs, David +1 more
Context. The first release of astrometric data from Gaia is expected in 2016. It will contain the mean stellar positions and magnitudes from the first year of observations. For more than 100 000 stars in common with the Hipparcos Catalogue it will be possible to compute very accurate proper motions due to the time difference of about 24 years betw…
Rigorous treatment of barycentric stellar motion. Perspective and light-time effects in astrometric and radial velocity data
Lindegren, L.; Butkevich, A. G.
Context. High-precision astrometric and radial-velocity observations require accurate modelling of stellar motions in order to extrapolate measurements over long time intervals, and to detect deviations from uniform motion caused, for example, by unseen companions.
Aims: We aim to explore the simplest possible kinematic model of stellar motio…
Large-scale environments of binary AGB stars probed by Herschel. II. Two companions interacting with the wind of π1 Gruis
Cruzalèbes, P.; Jorissen, A.; Pourbaix, D. +12 more
Context. The Mass loss of Evolved StarS (MESS) sample observed with PACS on board the Herschel Space Observatory revealed that several asymptotic giant branch (AGB) stars are surrounded by an asymmetric circumstellar envelope (CSE) whose morphology is most likely caused by the interaction with a stellar companion. The evolution of AGB stars in bin…
Searching for faint companions with VLTI/PIONIER. II. 92 main sequence stars from the Exozodi survey
Absil, O.; Augereau, J. -C.; Ertel, S. +6 more
Context. The Exozodi survey aims to determine the occurrence rate of bright exozodiacal discs around nearby main sequence stars using infrared interferometry. Although the Exozodi survey targets have been carefully selected to avoid the presence of binary stars, the results of this survey can still be biased by the presence of unidentified stellar…
Planetary companions in K giants β Cancri, µ Leonis, and β Ursae Minoris
Hatzes, A. P.; Lee, B. -C.; Park, M. -G. +3 more
Aims: The aim of our paper is to investigate the low-amplitude and long-period variations in evolved stars with a precise radial velocity survey.
Methods: The high-resolution, the fiber-fed Bohyunsan Observatory Echelle Spectrograph (BOES) was used from 2003 to 2013 for a radial velocity survey of giant stars as part of the exoplanet sea…
First detection of rotational CO line emission in a red giant branch star
Groenewegen, M. A. T.
Context. For stars with initial masses below ~1 M⊙, the mass loss during the first red giant branch (RGB) phase dominates mass loss in the later asymptotic giant branch (AGB) phase. Nevertheless, mass loss on the RGB is still often parameterised by a simple Reimers law in stellar evolution models.
Aims: To try to detect CO thermal …
IP Eridani: A surprising long-period binary system hosting a He white dwarf
Jorissen, A.; Masseron, T.; Van Winckel, H. +3 more
We determine the orbital elements for the K0 IV + white dwarf (WD) system IP Eri, which appears to have a surprisingly long period of 1071 d and a significant eccentricity of 0.25. Previous spectroscopic analyses of the WD, based on a distance of 101 pc inferred from its Hipparcos parallax, yielded a mass of only 0.43 M⊙, implying it to…