Search Publications
Gaia Data Release 3. Astrometric orbit determination with Markov chain Monte Carlo and genetic algorithms: Systems with stellar, sub-stellar, and planetary mass companions
Holl, B.; Sahlmann, J.; Sozzetti, A. +8 more
Context. The astrometric discovery of sub-stellar mass companions orbiting stars is exceedingly hard due to the required sub-milliarcsecond precision, limiting the application of this technique to only a few instruments on a target-per-target basis and to the global astrometry space missions HIPPARCOS and Gaia. The third Gaia data release (Gaia DR…
AF Lep b: The lowest-mass planet detected by coupling astrometric and direct imaging data
Kervella, P.; D'Orazi, V.; Zurlo, A. +6 more
Aims: Using the direct-imaging technique, we searched for low-mass companions around the star AF Lep, which presents a significant proper-motion anomaly (PMa) signal obtained from the comparison of HIPPARCOS and Gaia eDR3 catalogs.
Methods: We observed AF Lep in two epochs with VLT/SPHERE using its subsystems IFS and IRDIS in the near-in…
Direct imaging discovery of a super-Jovian around the young Sun-like star AF Leporis
De Rosa, Robert J.; Nielsen, Eric L.; Hirsch, Lea A. +5 more
Context. Expanding the sample of directly imaged companions to nearby, young stars that are amenable to detailed astrometric and spectroscopic studies is critical for the continued development and validation of theories of their evolution and atmospheric processes.
Aims: The recent release of the Gaia astrometric catalog allows us to efficien…
The Fifth Catalogue of Nearby Stars (CNS5)
Reffert, Sabine; Golovin, Alex; Vani, Akash +3 more
Context. We present the compilation of the Fifth Catalogue of Nearby Stars (CNS5), based on astrometric and photometric data from Gaia EDR3 and HIPPARCOS and supplemented with parallaxes from ground-based astrometric surveys carried out in the infrared.
Aims: The aim of the CNS5 is to provide the most complete sample of objects in the solar n…
Gaia Data Release 3. GRVS photometry from the RVS spectra
Smith, M.; Caffau, E.; Jordi, C. +38 more
Context.Gaia Data Release 3 (DR3) contains the first release of magnitudes estimated from the integration of Radial Velocity Spectrometer (RVS) spectra for a sample of about 32.2 million stars brighter than GRVS ∼ 14 mag (or G ∼ 15 mag).
Aims: In this paper, we describe the data used and the approach adopted to derive and validate …
Peering into the young planetary system AB Pic. Atmosphere, orbit, obliquity, and second planetary candidate
Ginski, C.; Homeier, D.; Zhang, Y. +24 more
Aims: We aim to revisit the formation pathway of AB Pic b, an imaged companion that straddles the exoplanet/brown-dwarf boundary. We based this study on a rich set of observations, which allows us to investigate its orbital and atmospheric properties.
Methods: We composed a spectrum of AB Pic b by merging archival medium-resolution (~400…
Barium and related stars, and their white-dwarf companions. III. The masses of the white dwarfs
Escorza, A.; De Rosa, R. J.
Context. Masses are one of the most difficult stellar properties to measure. In the case of the white-dwarf (WD) companions of Barium (Ba) stars, the situation is worse. These stars are dim, cool, and difficult to observe via direct methods. However, Ba stars were polluted by the asymptotic giant branch (AGB) progenitors of these WDs with matter r…
Updated characterization of long-period single companion by combining radial velocity, relative astrometry, and absolute astrometry
Kiefer, F.; Lagrange, A. -M.; Rubini, P. +2 more
Context. Thanks to more than 20 yr of monitoring, the radial velocity (RV) method has detected long-period companions (P > 10 yr) around several dozens of stars. Yet, the true nature of these companions remains unclear because of the uncertainty as to the inclination of the companion orbital plane.
Aims: We wish to constrain the orbital in…
Combining HIPPARCOS and Gaia data for the study of binaries: The BINARYS tool
Arenou, F.; Babusiaux, C.; van Leeuwen, F. +6 more
Context. Orbital motion in binary and planetary systems is the main source of precise stellar and planetary mass measurements, and the joint analysis of data obtained using multiple observational methods can both lift degeneracies and improve precision.
Aims: We set out to measure the masses of individual stars in binary systems using all the…
Multiples among B stars in the Scorpius-Centaurus association
D'Orazi, V.; Nascimbeni, V.; Janson, M. +14 more
Context. The frequency, semi-major axis, and mass distribution of stellar companions likely depend on the mass of the primaries and on the environment where the stars form. These properties are very different for early- and late-type stars. However, data are largely incomplete, even for the closest environments to the Sun, preventing a cleaner vie…