Gaia Data Release 2

  title={Gaia Data Release 2},
  author={Daniel Martin Katz and Paola Sartoretti and Mark S. Cropper and Pasquale Panuzzo and George Seabroke and Y. P. Viala and Kevin Benson and R. Blomme and G{\'e}rard Jasniewicz and A. Jean-Antoine and Howard E. Huckle and M. W. L. Smith and Stephen Baker and F. Crifo and Yassine Damerdji and M. David and Chris Dolding and Yves Fr{\'e}mat and Eric Gosset and A. Guerrier and Leanne P. Guy and R{\'e}gis Haigron and Katja Janssen and Olivier Marchal and G. Plum and C. Soubiran and F. Th{\'e}venin and M. Ajaj and Carlos Allende Prieto and C. Babusiaux and Steve Boudreault and Laurent Chemin and Claire Delle Luche and Caroline Fabre and Alain Gueguen and Nigel C. Hambly and Yannick Lasne and Fr{\'e}d{\'e}ric Meynadier and Fr{\'e}d{\'e}ric Pailler and Chantal Panem and Fr{\'e}d{\'e}ric Royer and G. Tauran and Christine Zurbach and Toma{\vz} Zwitter and Fr{\'e}d{\'e}ric Arenou and Diego Bossini and Joris Gerssen and Ana E. G{\'o}mez and Vincent Lema{\^i}tre and Nicolas Leclerc and Thierry Morel and U. Munari and C. Turon and Antonella Vallenari},
Context. For Gaia DR2, 280 million spectra collected by the Radial Velocity Spectrometer instrument on board Gaia were processed, and median radial velocities were derived for 9.8 million sources brighter than GRVS = 12 mag. Aims. This paper describes the validation and properties of the median radial velocities published in Gaia DR2. Methods. Quality tests and filters were applied to select those of the 9.8 million radial velocities that have the quality to be published in Gaia DR2. The… 

Determination of stellar parameters for Ariel targets: a comparison analysis between different spectroscopic methods

This work presents the results of a bench-marking analysis between three different spectroscopic techniques used to determine stellar parameters for a selected number of targets belonging to the Ariel reference sample and aims to consolidate a method that will be used to homogeneously determine the stellar parameters of the complete Ariel Reference sample.

X-ray Emission from Stars ∼The Results Obtained with MAXI∼

The Japanese astrophysical payload MAXI (Monitor of All-sky X-ray Image) has been monitor- ing the variable X-ray sky since August 15, 2009 from the International Space Station. With the 10 year’s

Globular clusters in the inner Galaxy classified from dynamical orbital criteria

Globular clusters (GCs) are the most ancient stellar systems in the Milky Way. Therefore, they play a key role in the understanding of the early chemical and dynamical evolution of our Galaxy.

High-Resolution Optical Spectroscopy of the Post-AGB Supergiant V340 Ser ($${\mathbf{=}}$$IRAS 17279$$\mathbf{-}$$1119)

Some evidences of wind variability and velocity stratification in the extended atmosphere has been found in the spectra of the supergiant V340 Ser (=IRAS 17279$-$1119) taken at the 6-m BTA telescope

Which stars can see Earth as a transiting exoplanet?

Transit observations have found the majority of exoplanets to date. Spectroscopic observations of transits and eclipses are the most commonly used tool to characterize exoplanet atmospheres and will

An extended halo around an ancient dwarf galaxy

The Milky Way is surrounded by dozens of ultra-faint ( 2 half-light radii), which are spectroscopically unstudied due to the sparseness of their distant stars. Here we identify members of the Tucana

The Demographics of Wide-Separation Planets

I begin this review by first defining what is meant by exoplanet demographics, and then motivating why we would like as broad a picture of exoplanet demographics as possible. I then outline the

A Review of Possible Planetary Atmospheres in the TRAPPIST-1 System

It is shown that (i) Hubble Space Telescope transit observations, (ii) bulk density measurements comparison with H2-rich planets mass-radius relationships, (iii) atmospheric escape modelling, and (iv) gas accretion modelling altogether offer solid evidence against the presence of hydrogen-dominated—cloud-free and cloudy—atmospheres around TRAPPIST-1 planets.

Gaia DR2 giants in the Galactic dust – I. Reddening across the whole dust layer and some properties of the giant clump

We consider a complete sample of 101810 giants with Gaia DR2 parallaxes $\varpi$ within the red clump domain of the Hertzsprung-Russell diagram in the space cylinder with a radius of 700 pc around



Michigan catalogue of two-dimensional spectral types for the HD stars

An improved machining center including an automatic tool changer adapted for boring, drilling, milling, tapping and tool changing operations under numerical control. The machine, which may be built

2018, A&A, 616, A4 (Gaia 2 SI) Gaia Collaboration (Prusti, T., et al.) 2016a, A&A

  • Res. Astron. Astrophys,
  • 2012

An der Sternwarte 16, 14482 Potsdam

    Jadranska ulica 19, 1000 Ljubljana, Slovenia 25 INAF-Osservatorio Astronomico di Padova, vicolo Osservatorio 5, 35122 Padova, Italy 26 INAF Astronomical Observatory of Padova

    • 24 Faculty of Mathematics and Physics

    2018a, A&A, 616, A1 (Gaia 2 SI) Gaia Collaboration (Babusiaux, C., et al.) 2018b, A&A

    • The Messenger,
    • 2012

    Egmont 5, 1000 Brussels, Belgium 10 Thales Services for CNES Centre Spatial de Toulouse, 18 avenue Edouard Belin, 31401 Toulouse Cedex 9

      Place Eugène Bataillon, CC72, 34095 Montpellier Cedex 05, France 5 CNES Centre Spatial de Toulouse