Search Publications
A volume-limited survey of mCP stars within 100 pc - I. Fundamental parameters and chemical abundances
Wade, G. A.; Neiner, C.; Sikora, J. +1 more
We present the first results of a volume-limited survey of main-sequence (MS) magnetic chemically peculiar (mCP) stars. The sample consists of all identified intermediate-mass MS stars (mCP and non-mCP) within a heliocentric distance of 100 pc as determined using Hipparcos parallaxes. The two populations are compared in order to determine the uniq…
Detection of the nearest Jupiter analogue in radial velocity and astrometry data
Janson, Markus; Anglada-Escudé, Guillem; Feng, Fabo +4 more
The presence of Jupiter is crucial to the architecture of the Solar system and models underline this to be a generic feature of planetary systems. We find the detection of the difference between the position and motion recorded by the contemporary astrometric satellite Gaia and its precursor Hipparcos can be used to discover Jupiter-like planets. …
A catalogue of stellar diameters and fluxes for mid-infrared interferometry
Meisenheimer, K.; Matter, A.; Jaffe, W. +14 more
We present the Mid-infrared stellar Diameters and Fluxes compilation Catalogue (MDFC) dedicated to long-baseline interferometry at mid-infrared wavelengths (3-13 µm). It gathers data for half a million stars, i.e. nearly all the stars of the Hipparcos-Tycho catalogue whose spectral type is reported in the SIMBAD data base. We cross-match 26 …
Masses and radii for the three super-Earths orbiting GJ 9827, and implications for the composition of small exoplanets
Bouchy, F.; Vanderburg, A.; Poretti, E. +34 more
Super-Earths belong to a class of planet not found in the Solar system, but which appear common in the Galaxy. Given that some super-Earths are rocky, while others retain substantial atmospheres, their study can provide clues as to the formation of both rocky and gaseous planets, and - in particular - they can help to constrain the role of photoev…
The magnetic early B-type Stars II: stellar atmospheric parameters in the era of Gaia
Wade, G. A.; Neiner, C.; Shultz, M. E. +6 more
Atmospheric parameters determined via spectral modelling are unavailable for many of the known magnetic early B-type stars. We utilized high-resolution spectra together with non-local thermodynamic equilibrium models to measure effective temperatures Teff and surface gravities log g of stars for which these measurements are not yet avai…
Triage of astrometric binaries - how to find triple systems and dormant black hole secondaries in the Gaia orbits
Mazeh, T.; Holl, B.; Faigler, S. +1 more
Preparing for the expected wealth of Gaia detections, we consider here a simple algorithm for classifying unresolved astrometric binaries with main-sequence (MS) primary into three classes: binaries with a probable MS secondary, with two possible values for the mass ratio; probable hierarchical triple MS systems with an astrometric secondary as a …
The compact multiple system HIP 41431
Molnár, L.; Latham, D. W.; Tokovinin, A. +4 more
The nearby (50 pc) K7V dwarf HIP 41431 (EPIC 212096658) is a compact three-tier hierarchy. Three K7V stars with similar masses, from 0.61 to 0.63 solar, make a triple-lined spectroscopic system where the inner binary with a period of 2.9 d is eclipsing, and the outer companion on a 59-d orbit exerts strong dynamical influence revealed by the eclip…
Interstellar polarization and extinction in the Local Bubble and the Gould Belt
Gontcharov, George A.; Mosenkov, Aleksandr V.
We analyse an all-sky compilation of 13 data sources with optical interstellar linear polarization for 3871 Gaia DR2 and Hipparcos stars within 500 pc, which do not exhibit a considerable intrinsic polarization. These data are analysed together with five 3D maps and models of the reddening E(B - V). We consider variations of the polarization degre…
The distance, rotation, and physical parameters of ζ Pup
Howarth, Ian D.; van Leeuwen, Floor
We scrutinize the Hipparcos parallax for the bright O supergiant ζ Pup and confirm that the implied distance of 332 ± 11 pc appears to be reliable. We then review the implications for the star's physical parameters and the consequences for the interpretation of Pphot, the 1.78-d photometric period. The inferred mass, radius, and luminos…
Spectroscopic and astrometric radial velocities: Hyades as a benchmark
Pasquini, L.; Ludwig, H. -G.; de Medeiros, J. R. +1 more
We study the accuracy of spectroscopic radial velocities (RVs) by comparing spectroscopic and astrometric RVs for stars of the Hyades open cluster. We obtained High-Accuracy Radial velocity Planet Searcher (HARPS) spectra for a large sample of Hyades stars and combined them with accurate astrometric RVs based on Hipparcos and Gaia data. After clea…