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Concept

Astrométrie

Publications associées (16)

Gaia Focused Product Release: Asteroid orbital solution: Properties and assessment

Stephan Morgenthaler, Shuangqing Liao

Context. We report the exploitation of a sample of Solar System observations based on data from the third Gaia Data Release (Gaia DR3) of nearly 157 000 asteroids. It extends the epoch astrometric solution over the time coverage planned for the Gaia DR4, w ...

Edp Sciences S A2023

HD 213258: A new rapidly oscillating, super slowly rotating, strongly magnetic Ap star in a spectroscopic binary

Pierre North

We report on HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at seven epochs spanning a time interval slightly sho ...

EDP SCIENCES S A2023

Gaia Data Release 3: The extragalactic content

Richard Irving Anderson, Shuangqing Liao, Mária Süveges, Pablo Jose Fernandez Marcos

The Gaia Galactic survey mission is designed and optimized to obtain astrometry, photometry, and spectroscopy of nearly two billion stars in our Galaxy. Yet as an all-sky multi-epoch survey, Gaia also observes several million extragalactic objects down to ...

2023

Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era

Pierre North

Context. Li is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. Aims. We present the results of a new large Li survey in red giant stars and combine it with surveys from the literature to probe the impa ...

EDP SCIENCES S A2020

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. ...

EDP SCIENCES S A2019

Barium and related stars, and their white-dwarf companions

Pierre North, Conrad Johnston, Shreeya Sushil Shetye

Barium (Ba) dwarfs and CH subgiants are the less evolved analogues of Ba and CH giants. They are F- to G-type main-sequence stars polluted with heavy elements by their binary companions when the companion was on the asymptotic giant branch (AGB). This comp ...

EDP SCIENCES S A2019

The Dark Energy Survey: Data Release 1

Yi Zhang, Xin Chen, Eduardo Sanchez, Craig Matthew Smith, Jonathan Andrew Blazek, Aaron James Rossini, Jennifer Kaitlyn Olsen, Augusto Martins Lima, Josiane Angèle Charlotte Smith-Clerc, Vikram Vinayak Karve, Xi Chen, Juan Andrei Villarroel Fernandez, Vanda Carla Costa Grisel

We describe the first public data release of the Dark Energy Survey, DES DR1, consisting of reduced single-epoch images, co-added images, co-added source catalogs, and associated products and services assembled over the first 3 yr of DES science operations ...

IOP PUBLISHING LTD2018

Gaia Data Release 1 Open cluster astrometry: performance, limitations, and future prospects

Stephan Morgenthaler, Shuangqing Liao

Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 po ...

Edp Sciences S A2017

Testing parallaxes with local Cepheids and RR Lyrae stars

Stephan Morgenthaler, Shuangqing Liao

Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Ai ...

Edp Sciences S A2017

Structure of Herbig AeBe Disks at the milliarcsecond Scale—A Statistical Survey in the H Band Using PIONIER-VLTI

Ferréol Arnaud Marie Soulez

Context. It is now generally accepted that the near-infrared excess of Herbig AeBe stars originates in the dust of a circumstellar disk. Aims. The aims of this article are to infer the radial and vertical structure of these disks at scales of order 1 au, a ...

ESO2017

Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties

Stephan Morgenthaler, Shuangqing Liao

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illu ...

EDP Sciences2016

The ESPRI project: astrometric exoplanet search with PRIMA I. Instrument description and performance of first light observations

Ludger Weber

Context. The ESPRI project relies on the astrometric capabilities offered by the PRIMA facility of the Very Large Telescope Interferometer for discovering and studying planetary systems. Our survey consists of obtaining high-precision astrometry for a larg ...

Edp Sciences S A2013

The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets

Malte Tewes

Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory. Aims. With an observing time span of more than 14 years, the ...

Edp Sciences S A2013

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses X. Modeling based on high-precision astrometry of a sample of 25 lensed quasars: consequences for ellipticity, shear, and astrometric anomalies

Frédéric Courbin, Georges Meylan

Gravitationally lensed quasars can be used as powerful cosmological and astrophysical probes. We can (i) infer the Hubble constant H-0 based on the so-called time-delay technique, (ii) unveil substructures along the line-of-sight toward distant galaxies, a ...

2012

A deep proper-motion survey of the nearby open cluster Blanco 1

Jean-Claude Mermilliod

We provide two comprehensive catalogues of positions and proper motions in the area of open cluster Blanco 1. The main catalogue, CtlgM, contains 6271 objects down to V similar to 18.5 and covers a circular similar to 11 deg2 area. The accuracy of CtlgM pr ...

Blackwell Publishing Ltd, Oxford2011

A sharp look at the gravitationally lensed quasar SDSS J0806+2006 with laser guide star adaptive optics at the VLT

Frédéric Courbin, Georges Meylan, Alexander Patrick Eigenbrod

We present the first VLT near-IR observations of a gravitationally lensed quasar, using adaptive optics and laser guide star. These observations can be considered as a test bench for future systematic observations of lensed quasars with adaptive optics, ev ...

2008