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1. PREPARING FOR THE GAIA MISSION: ASTROPHYSICAL PARAMETER DETERMINATION

Author: Brown, A.G.A., primary
Published: 2020
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2. Estimating the selection function of Gaia DR3 subsamples

Author: Castro-Ginard, A., primary, Brown, A.G.A., additional, Kostrzewa-Rutkowska, Z., additional, Cantat-Gaudin, T., additional, Drimmel, R., additional, Oh, S., additional, Belokurov, V., additional, Casey, A.R., additional, Fouesneau, M., additional, Khanna, S., additional, Price-Whelan, A.M., additional, and Rix, H.W., additional
Published: 2023
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3. A 3D view of dwarf galaxies with Gaia and VLT/FLAMES. I. The Sculptor dwarf spheroidal

Author: Tolstoy, E., primary, Skúladóttir, Á., additional, Battaglia, G., additional, Brown, A.G.A., additional, Massari, D., additional, Irwin, M.J., additional, Starkenburg, E., additional, Salvadori, S., additional, Hill, V., additional, Jablonka, P., additional, Salaris, M., additional, van Essen, T., additional, Olsthoorn, C., additional, Helmi, A., additional, and Pritchard, J., additional
Published: 2023
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4. Gaia Data Release 3: Summary of the content and survey properties

Author: Vallenari, A., Brown, A.G.A., Prusti, T., Aerts, C., Zorec, J., Zucker, S., Zwitter, T., Vallenari, A., Brown, A.G.A., Prusti, T., Aerts, C., Zorec, J., Zucker, S., and Zwitter, T.
Abstract: Contains fulltext : 294446.pdf (Publisher’s version ) (Open Access)
Published: 2023

5. A machine-learning-based tool for open cluster membership determination in Gaia DR3

Author: Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Universidad de Barcelona, Groeningen, M. G. J. van, Castro-Ginard, Alfred, Brown, A.G.A., Casamiquela, Laia, Jordi, Carme, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), European Commission, Universidad de Barcelona, Groeningen, M. G. J. van, Castro-Ginard, Alfred, Brown, A.G.A., Casamiquela, Laia, and Jordi, Carme
Abstract: [Context] Membership studies characterising open clusters (OCs) with Gaia data – most of them using Gaia Data Release 2 (DR2) – have so far been limited at the faint end to magnitude G = 18 due to astrometric uncertainties., [Aims] Our goal is to extend current OC membership lists with faint members and to characterise the low-mass end. These low-mass members are important for many applications, in particular for ground-based spectroscopic surveys., [Methods] We use a deep neural network architecture to learn the distribution of highly reliable OC member stars around known clusters. We then use the trained network to estimate new OC members based on their similarities in a high dimensional space, their five-dimensional astrometry, and information from the three photometric bands., [Results] Due to the improved astrometric precision of Gaia Data Release 3 (DR3) with respect to DR2, we are able to homogeneously detect new faint member stars (G > 18) for the known OC population., [Conclusions] Our methodology can provide extended membership lists for OCs down to the limiting magnitude of Gaia, which will enable further studies to characterise the OC population; such as estimation of their masses and dynamics. These extended membership lists are also ideal target lists for forthcoming ground-based spectroscopic surveys.
Published: 2023

6. An attitude model for the spacecraft of the ESA mission Gaia

Author: Keil, R., Risquez, D., van Leeuwen, F., and Brown, A.G.A.
Published: 2011
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7. Updated catalog of class I late-type stars: Gaia EDR3

Author: Messineo M. and Brown A.G.A.
Subjects: stars: supergiants, massive stars, stars: evolution
Abstract: Here we describe on a revised version of the catalog of bright late-type stars by Messineo & Brown (2019) with Gaia EDR3 data., N/A
Published: 2021
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8. Gaia Early Data Release 3: Acceleration of the Solar System from Gaia astrometry

Author: Klioner, S.A. Mignard, F. Lindegren, L. Bastian, U. McMillan, P.J. Hernández, J. Hobbs, D. Ramos-Lerate, M. Biermann, M. Bombrun, A. De Torres, A. Gerlach, E. Geyer, R. Hilger, T. Lammers, U. Steidelmüller, H. Stephenson, C.A. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Creevey, O.L. Evans, D.W. Eyer, L. Hutton, A. Jansen, F. Jordi, C. Luri, X. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Walton, N.A. Arenou, F. Bailer-Jones, C.A.L. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Van Leeuwen, F. Bakker, J. Castañeda, J. De Angeli, F. Ducourant, C. Fabricius, C. Fouesneau, M. Frémat, Y. Guerra, R. Guerrier, A. Guiraud, J. Jean-Antoine Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nicolas, C. Nienartowicz, K. Pailler, F. Panuzzo, P. Riclet, F. Roux, W. Seabroke, G.M. Sordo, R. Tanga, P. Thévenin, F. Gracia-Abril, G. Portell, J. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Brugaletta, E. Burgess, P.W. Busso, G. Carry, B. Cellino, A. Cheek, N. Clementini, G. Damerdji, Y. Davidson, M. Delchambre, L. Dell'Oro, A. Fernández-Hernández, J. Galluccio, L. García-Lario, P. Garcia-Reinaldos, M. González-Núñez, J. Gosset, E. Haigron, R. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hatzidimitriou, D. Heiter, U. Hestroffer, D. Hodgkin, S.T. Holl, B. Janßen, K. Jevardat De Fombelle, G. Jordan, S. Krone-Martins, A. Lanzafame, A.C. Löffler, W. Lorca, A. Manteiga, M. Marchal, O. Marrese, P.M. Moitinho, A. Mora, A. Muinonen, K. Osborne, P. Pancino, E. Pauwels, T. Recio-Blanco, A. Richards, P.J. Riello, M. Rimoldini, L. Robin, A.C. Roegiers, T. Rybizki, J. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Ulla, A. Utrilla, E. Van Leeuwen, M. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Aguado, J.J. Ajaj, M. Altavilla, G. Álvarez, M.A. Álvarez Cid-Fuentes, J. Alves, J. Anderson, R.I. Anglada Varela, E. Antoja, T. Audard, M. Baines, D. Baker, S.G. Balaguer-Núñez, L. Balbinot, E. Balog, Z. Barache, C. Barbato, D. Barros, M. Barstow, M.A. Bartolomé, S. Bassilana, J.-L. Bauchet, N. Baudesson-Stella, A. Becciani, U. Bellazzini, M. Bernet, M. Bertone, S. Bianchi, L. Blanco-Cuaresma, S. Boch, T. Bossini, D. Bouquillon, S. Bramante, L. Breedt, E. Bressan, A. Brouillet, N. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cánovas, H. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carnerero, M.I. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Castro Sampol, P. Chaoul, L. Charlot, P. Chemin, L. Chiavassa, A. Comoretto, G. Cooper, W.J. Cornez, T. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Dafonte, C. Dapergolas, A. David, M. David, P. De Laverny, P. De Luise, F. De March, R. De Ridder, J. De Souza, R. De Teodoro, P. Del Peloso, E.F. Del Pozo, E. Delgado, A. Delgado, H.E. Delisle, J.-B. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Eappachen, D. Enke, H. Esquej, P. Fabre, C. Fabrizio, M. Faigler, S. Fedorets, G. Fernique, P. Fienga, A. Figueras, F. Fouron, C. Fragkoudi, F. Fraile, E. Franke, F. Gai, M. Garabato, D. Garcia-Gutierrez, A. García-Torres, M. Garofalo, A. Gavras, P. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomez, A. Gonzalez-Santamaria, I. González-Vidal, J.J. Granvik, M. Gutiérrez-Sánchez, R. Guy, L.P. Hauser, M. Haywood, M. Helmi, A. Hidalgo, S.L. Hładczuk, N. Holland, G. Huckle, H.E. Jasniewicz, G. Jonker, P.G. Juaristi Campillo, J. Julbe, F. Karbevska, L. Kervella, P. Khanna, S. Kochoska, A. Kordopatis, G. Korn, A.J. Kostrzewa-Rutkowska, Z. Kruszyńska, K. Lambert, S. Lanza, A.F. Lasne, Y. Le Campion, J.-F. Le Fustec, Y. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Madrero Pardo, P. Managau, S. Mann, R.G. Marchant, J.M. Marconi, M. Marcos Santos, M.M.S. Marinoni, S. Marocco, F. Marshall, D.J. Martin Polo, L. Martín-Fleitas, J.M. Masip, A. Massari, D. Mastrobuono-Battisti, A. Mazeh, T. Messina, S. Michalik, D. Millar, N.R. Mints, A. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Munoz, D. Muraveva, T. Murphy, C.P. Musella, I. Noval, L. Ordénovic, C. Orrù, G. Osinde, J. Pagani, C. Pagano, I. Palaversa, L. Palicio, P.A. Panahi, A. Pawlak, M. Peñalosa Esteller, X. Penttilä, A. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poretti, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rainer, M. Raiteri, C.M. Rambaux, N. Ramos, P. Re Fiorentin, P. Regibo, S. Reylé, C. Ripepi, V. Riva, A. Rixon, G. Robichon, N. Robin, C. Roelens, M. Rohrbasser, L. Romero-Gómez, M. Rowell, N. Royer, F. Rybicki, K.A. Sadowski, G. Sagristà Sellés, A. Sahlmann, J. Salgado, J. Salguero, E. Samaras, N. Sanchez Gimenez, V. Sanna, N. Santoveña, R. Sarasso, M. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Semeux, D. Siddiqui, H.I. Siebert, A. Siltala, L. Slezak, E. Smart, R.L. Solano, E. Solitro, F. Souami, D. Souchay, J. Spagna, A. Spoto, F. Steele, I.A. Süveges, M. Szabados, L. Szegedi-Elek, E. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Thuillot, W. Tonello, N. Torra, F. Torra, J. Turon, C. Unger, N. Vaillant, M. Van Dillen, E. Vanel, O. Vecchiato, A. Viala, Y. Vicente, D. Voutsinas, S. Weiler, M. Wevers, T. Wyrzykowski, L. Yoldas, A. Yvard, P. Zhao, H. Zorec, J. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: Context. Gaia Early Data Release 3 (Gaia EDR3) provides accurate astrometry for about 1.6 million compact (QSO-like) extragalactic sources, 1.2 million of which have the best-quality five-parameter astrometric solutions. Aims. The proper motions of QSO-like sources are used to reveal a systematic pattern due to the acceleration of the solar systembarycentre with respect to the rest frame of the Universe. Apart from being an important scientific result by itself, the acceleration measured in this way is a good quality indicator of the Gaia astrometric solution. Methods. Theeffect of the acceleration was obtained as a part of the general expansion of the vector field of proper motions in vector spherical harmonics (VSH). Various versions of the VSH fit and various subsets of the sources were tried and compared to get the most consistent result and a realistic estimate of its uncertainty. Additional tests with the Gaia astrometric solution were used to get a better idea of the possible systematic errors in the estimate. Results. Our best estimate of the acceleration based on Gaia EDR3 is (2.32 ± 0.16) × 10-10 m s-2 (or 7.33 ±0.51 km s-1 Myr-1) towards α = 269.1° ± 5.4°, δ = -31.6° ± 4.1°, corresponding to a proper motion amplitude of 5.05 ±0.35 μas yr-1. This is in good agreement with the acceleration expected from current models of the Galactic gravitational potential. We expect that future Gaia data releases will provide estimates of the acceleration with uncertainties substantially below 0.1 μas yr-1. © ESO 2021.
Published: 2021

9. Gaia Early Data Release 3: Structure and properties of the Magellanic Clouds

Author: Luri, X. Chemin, L. Clementini, G. Delgado, H.E. McMillan, P.J. Romero-Gómez, M. Balbinot, E. Castro-Ginard, A. Mor, R. Ripepi, V. Sarro, L.M. Cioni, M.-R.L. Fabricius, C. Garofalo, A. Helmi, A. Muraveva, T. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Biermann, M. Creevey, O.L. Evans, D.W. Eyer, L. Hutton, A. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Walton, N.A. Arenou, F. Bailer-Jones, C.A.L. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Van Leeuwen, F. Bakker, J. Castañeda, J. De Angeli, F. Ducourant, C. Fouesneau, M. Frémat, Y. Guerra, R. Guerrier, A. Guiraud, J. Jean-Antoine Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nicolas, C. Nienartowicz, K. Pailler, F. Panuzzo, P. Riclet, F. Roux, W. Seabroke, G.M. Sordo, R. Tanga, P. Thévenin, F. Gracia-Abril, G. Portell, J. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Brugaletta, E. Burgess, P.W. Busso, G. Carry, B. Cellino, A. Cheek, N. Damerdji, Y. Davidson, M. Delchambre, L. Dell'Oro, A. Fernández-Hernández, J. Galluccio, L. García-Lario, P. Garcia-Reinaldos, M. González-Núñez, J. Gosset, E. Haigron, R. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hatzidimitriou, D. Heiter, U. Hernández, J. Hestroffer, D. Hodgkin, S.T. Holl, B. Janßen, K. Jevardat De Fombelle, G. Jordan, S. Krone-Martins, A. Lanzafame, A.C. Löffler, W. Lorca, A. Manteiga, M. Marchal, O. Marrese, P.M. Moitinho, A. Mora, A. Muinonen, K. Osborne, P. Pancino, E. Pauwels, T. Recio-Blanco, A. Richards, P.J. Riello, M. Rimoldini, L. Robin, A.C. Roegiers, T. Rybizki, J. Siopis, C. Smith, M. Sozzetti, A. Ulla, A. Utrilla, E. Van Leeuwen, M. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Aguado, J.J. Ajaj, M. Altavilla, G. Álvarez, M.A. Álvarez Cid-Fuentes, J. Alves, J. Anderson, R.I. Anglada Varela, E. Antoja, T. Audard, M. Baines, D. Baker, S.G. Balaguer-Núñez, L. Balog, Z. Barache, C. Barbato, D. Barros, M. Barstow, M.A. Bartolomé, S. Bassilana, J.-L. Bauchet, N. Baudesson-Stella, A. Becciani, U. Bellazzini, M. Bernet, M. Bertone, S. Bianchi, L. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Bossini, D. Bouquillon, S. Bragaglia, A. Bramante, L. Breedt, E. Bressan, A. Brouillet, N. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cánovas, H. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carnerero, M.I. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro Sampol, P. Chaoul, L. Charlot, P. Chiavassa, A. Comoretto, G. Cooper, W.J. Cornez, T. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Dafonte, C. Dapergolas, A. David, M. David, P. De Laverny, P. De Luise, F. De March, R. De Ridder, J. De Souza, R. De Teodoro, P. De Torres, A. Del Peloso, E.F. Del Pozo, E. Delgado, A. Delisle, J.-B. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Eappachen, D. Enke, H. Esquej, P. Fabre, C. Fabrizio, M. Faigler, S. Fedorets, G. Fernique, P. Fienga, A. Figueras, F. Fouron, C. Fragkoudi, F. Fraile, E. Franke, F. Gai, M. Garabato, D. Garcia-Gutierrez, A. García-Torres, M. Gavras, P. Gerlach, E. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomez, A. Gonzalez-Santamaria, I. González-Vidal, J.J. Granvik, M. Gutiérrez-Sánchez, R. Guy, L.P. Hauser, M. Haywood, M. Hidalgo, S.L. Hilger, T. Hładczuk, N. Hobbs, D. Holland, G. Huckle, H.E. Jasniewicz, G. Jonker, P.G. Juaristi Campillo, J. Julbe, F. Karbevska, L. Kervella, P. Khanna, S. Kochoska, A. Kontizas, M. Kordopatis, G. Korn, A.J. Kostrzewa-Rutkowska, Z. Kruszyńska, K. Lambert, S. Lanza, A.F. Lasne, Y. Le Campion, J.-F. Le Fustec, Y. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Madrero Pardo, P. Managau, S. Mann, R.G. Marchant, J.M. Marconi, M. Marcos Santos, M.M.S. Marinoni, S. Marocco, F. Marshall, D.J. Martin Polo, L. Martín-Fleitas, J.M. Masip, A. Massari, D. Mastrobuono-Battisti, A. Mazeh, T. Messina, S. Michalik, D. Millar, N.R. Mints, A. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Munoz, D. Murphy, C.P. Musella, I. Noval, L. Ordénovic, C. Orrù, G. Osinde, J. Pagani, C. Pagano, I. Palaversa, L. Palicio, P.A. Panahi, A. Pawlak, M. Peñalosa Esteller, X. Penttilä, A. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poretti, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rainer, M. Raiteri, C.M. Rambaux, N. Ramos, P. Ramos-Lerate, M. Re Fiorentin, P. Regibo, S. Reylé, C. Riva, A. Rixon, G. Robichon, N. Robin, C. Roelens, M. Rohrbasser, L. Rowell, N. Royer, F. Rybicki, K.A. Sadowski, G. Sagristà Sellés, A. Sahlmann, J. Salgado, J. Salguero, E. Samaras, N. Gimenez, V.S. Sanna, N. Santoveña, R. Sarasso, M. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Semeux, D. Siddiqui, H.I. Siebert, A. Siltala, L. Slezak, E. Smart, R.L. Solano, E. Solitro, F. Souami, D. Souchay, J. Spagna, A. Spoto, F. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Süveges, M. Szabados, L. Szegedi-Elek, E. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Thuillot, W. Tonello, N. Torra, F. Torra, J. Turon, C. Unger, N. Vaillant, M. Van Dillen, E. Vanel, O. Vecchiato, A. Viala, Y. Vicente, D. Voutsinas, S. Weiler, M. Wevers, T. Wyrzykowski, L. Yoldas, A. Yvard, P. Zhao, H. Zorec, J. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: Context. This work is part of the Gaia Data Processing and Analysis Consortium papers published with the Gaia Early Data Release 3 (EDR3). It is one of the demonstration papers aiming to highlight the improvements and quality of the newly published data by applying them to a scientific case. Aims. We use the Gaia EDR3 data to study the structure and kinematics of the Magellanic Clouds. The large distance to the Clouds is a challenge for the Gaia astrometry. The Clouds lie at the very limits of the usability of the Gaia data, which makes the Clouds an excellent case study for evaluating the quality and properties of the Gaia data. Methods. The basis of our work are two samples selected to provide a representation as clean as possible of the stars of the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). The selection used criteria based on position, parallax, and proper motions to remove foreground contamination from the Milky Way, and allowed the separation of the stars of both Clouds. From these two samples we defined a series of subsamples based on cuts in the colour-magnitude diagram; these subsamples were used to select stars in a common evolutionary phase and can also be used as approximate proxies of a selection by age. Results. We compared the Gaia Data Release 2 and Gaia EDR3 performances in the study of the Magellanic Clouds and show the clear improvements in precision and accuracy in the new release. We also show that the systematics still present in the data make the determination of the 3D geometry of the LMC a difficult endeavour; this is at the very limit of the usefulness of the Gaia EDR3 astrometry, but it may become feasible with the use of additional external data. We derive radial and tangential velocity maps and global profiles for the LMC for the several subsamples we defined. To our knowledge, this is the first time that the two planar components of the ordered and random motions are derived for multiple stellar evolutionary phases in a galactic disc outside the Milky Way, showing the differences between younger and older phases. We also analyse the spatial structure and motions in the central region, the bar, and the disc, providing new insightsinto features and kinematics. Finally, we show that the Gaia EDR3 data allows clearly resolving the Magellanic Bridge, and we trace the density and velocity flow of the stars from the SMC towards the LMC not only globally, but also separately for young and evolved populations. This allows us to confirm an evolved population in the Bridge that is slightly shift from the younger population. Additionally, we were able to study the outskirts of both Magellanic Clouds, in which we detected some well-known features and indications of new ones. © ESO 2021.
Published: 2021

10. Gaia Early Data Release 3: The Gaia Catalogue of Nearby Stars

Author: Smart, R.L. Sarro, L.M. Rybizki, J. Reylé, C. Robin, A.C. Hambly, N.C. Abbas, U. Barstow, M.A. De Bruijne, J.H.J. Bucciarelli, B. Carrasco, J.M. Cooper, W.J. Hodgkin, S.T. Masana, E. Michalik, D. Sahlmann, J. Sozzetti, A. Brown, A.G.A. Vallenari, A. Prusti, T. Babusiaux, C. Biermann, M. Creevey, O.L. Evans, D.W. Eyer, L. Hutton, A. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Walton, N.A. Arenou, F. Bailer-Jones, C.A.L. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Van Leeuwen, F. Bakker, J. Castañeda, J. De Angeli, F. Ducourant, C. Fabricius, C. Fouesneau, M. Frémat, Y. Guerra, R. Guerrier, A. Guiraud, J. Jean-Antoine Piccolo, A. Messineo, R. Mowlavi, N. Nicolas, C. Nienartowicz, K. Pailler, F. Panuzzo, P. Riclet, F. Roux, W. Seabroke, G.M. Sordo, R. Tanga, P. Thévenin, F. Gracia-Abril, G. Portell, J. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Brugaletta, E. Burgess, P.W. Busso, G. Carry, B. Cellino, A. Cheek, N. Clementini, G. Damerdji, Y. Davidson, M. Delchambre, L. Dell'Oro, A. Fernández-Hernández, J. Galluccio, L. García-Lario, P. Garcia-Reinaldos, M. González-Núñez, J. Gosset, E. Haigron, R. Halbwachs, J.-L. Harrison, D.L. Hatzidimitriou, D. Heiter, U. Hernández, J. Hestroffer, D. Holl, B. Janßen, K. Jevardat De Fombelle, G. Jordan, S. Krone-Martins, A. Lanzafame, A.C. Löffler, W. Lorca, A. Manteiga, M. Marchal, O. Marrese, P.M. Moitinho, A. Mora, A. Muinonen, K. Osborne, P. Pancino, E. Pauwels, T. Recio-Blanco, A. Richards, P.J. Riello, M. Rimoldini, L. Roegiers, T. Siopis, C. Smith, M. Ulla, A. Utrilla, E. Van Leeuwen, M. Van Reeven, W. Abreu Aramburu, A. Accart, S. Aerts, C. Aguado, J.J. Ajaj, M. Altavilla, G. Álvarez, M.A. Álvarez Cid-Fuentes, J. Alves, J. Anderson, R.I. Anglada Varela, E. Antoja, T. Audard, M. Baines, D. Baker, S.G. Balaguer-Núñez, L. Balbinot, E. Balog, Z. Barache, C. Barbato, D. Barros, M. Bartolomé, S. Bassilana, J.-L. Bauchet, N. Baudesson-Stella, A. Becciani, U. Bellazzini, M. Bernet, M. Bertone, S. Bianchi, L. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Bossini, D. Bouquillon, S. Bragaglia, A. Bramante, L. Breedt, E. Bressan, A. Brouillet, N. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cánovas, H. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carnerero, M.I. Casamiquela, L. Castellani, M. Castro-Ginard, A. Castro Sampol, P. Chaoul, L. Charlot, P. Chemin, L. Chiavassa, A. Cioni, M.-R.L. Comoretto, G. Cornez, T. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Dafonte, C. Dapergolas, A. David, M. David, P. De Laverny, P. De Luise, F. De March, R. De Ridder, J. De Souza, R. De Teodoro, P. De Torres, A. Del Peloso, E.F. Del Pozo, E. Delgado, A. Delgado, H.E. Delisle, J.-B. DI Matteo, P. DIakite, S. DIener, C. DIstefano, E. Dolding, C. Eappachen, D. Edvardsson, B. Enke, H. Esquej, P. Fabre, C. Fabrizio, M. Faigler, S. Fedorets, G. Fernique, P. Fienga, A. Figueras, F. Fouron, C. Fragkoudi, F. Fraile, E. Franke, F. Gai, M. Garabato, D. Garcia-Gutierrez, A. García-Torres, M. Garofalo, A. Gavras, P. Gerlach, E. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomel, R. Gomez, A. Gonzalez-Santamaria, I. González-Vidal, J.J. Granvik, M. Gutiérrez-Sánchez, R. Guy, L.P. Hauser, M. Haywood, M. Helmi, A. Hidalgo, S.L. Hilger, T. Hładczuk, N. Hobbs, D. Holland, G. Huckle, H.E. Jasniewicz, G. Jonker, P.G. Juaristi Campillo, J. Julbe, F. Karbevska, L. Kervella, P. Khanna, S. Kochoska, A. Kontizas, M. Kordopatis, G. Korn, A.J. Kostrzewa-Rutkowska, Z. Kruszyńska, K. Lambert, S. Lanza, A.F. Lasne, Y. Le Campion, J.-F. Le Fustec, Y. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Madrero Pardo, P. Managau, S. Mann, R.G. Marchant, J.M. Marconi, M. Marcos Santos, M.M.S. Marinoni, S. Marocco, F. Marshall, D.J. Martin Polo, L. Martín-Fleitas, J.M. Masip, A. Massari, D. Mastrobuono-Battisti, A. Mazeh, T. McMillan, P.J. Messina, S. Millar, N.R. Mints, A. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Munoz, D. Muraveva, T. Murphy, C.P. Musella, I. Noval, L. Ordénovic, C. Orrù, G. Osinde, J. Pagani, C. Pagano, I. Palaversa, L. Palicio, P.A. Panahi, A. Pawlak, M. Peñalosa Esteller, X. Penttilä, A. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poretti, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rainer, M. Raiteri, C.M. Rambaux, N. Ramos, P. Ramos-Lerate, M. Re Fiorentin, P. Regibo, S. Ripepi, V. Riva, A. Rixon, G. Robichon, N. Robin, C. Roelens, M. Rohrbasser, L. Romero-Gómez, M. Rowell, N. Royer, F. Rybicki, K.A. Sadowski, G. Sagristà Sellés, A. Salgado, J. Salguero, E. Samaras, N. Sanchez Gimenez, V. Sanna, N. Santoveña, R. Sarasso, M. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Semeux, D. Shahaf, S. Siddiqui, H.I. Siebert, A. Siltala, L. Slezak, E. Solano, E. Solitro, F. Souami, D. Souchay, J. Spagna, A. Spoto, F. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Süveges, M. Szabados, L. Szegedi-Elek, E. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Thuillot, W. Tonello, N. Torra, F. Torra, J. Turon, C. Unger, N. Vaillant, M. Van DIllen, E. Vanel, O. Vecchiato, A. Viala, Y. Vicente, D. Voutsinas, S. Weiler, M. Wevers, T. Wyrzykowski, L. Yoldas, A. Yvard, P. Zhao, H. Zorec, J. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: Aims. We produce a clean and well-characterised catalogue of objects within 100 pc of the Sun from the Gaia Early Data Release 3. We characterise the catalogue through comparisons to the full data release, external catalogues, and simulations. We carry out a first analysis of the science that is possible with this sample to demonstrate its potential and best practices for its use. Methods. Theselection of objects within 100 pc from the full catalogue used selected training sets, machine-learning procedures, astrometric quantities, and solution quality indicators to determine a probability that the astrometric solution is reliable. The training set construction exploited the astrometric data, quality flags, and external photometry. For all candidates we calculated distance posterior probability densities using Bayesian procedures and mock catalogues to define priors. Any object with reliable astrometry and a non-zero probability of being within 100 pc is included in the catalogue. Results. We have produced a catalogue of 331 312 objects that we estimate contains at least 92% of stars of stellar type M9 within 100 pc of the Sun. We estimate that 9% of the stars in this catalogue probably lie outside 100 pc, but when the distance probability function is used, a correct treatment of this contamination is possible. We produced luminosity functions with a high signal-to-noise ratio for the main-sequence stars, giants, and white dwarfs. We examined in detail the Hyades cluster, the white dwarf population, and wide-binary systems and produced candidate lists for all three samples. We detected local manifestations of several streams, superclusters, and halo objects, in which we identified 12 members of Gaia Enceladus. We present the first direct parallaxes of five objects in multiple systems within 10 pc of the Sun. Conclusions. We provide the community with a large, well-characterised catalogue of objects in the solar neighbourhood. This is a primary benchmark for measuring and understanding fundamental parameters and descriptive functions in astronomy. © ESO 2021.
Published: 2021

11. Gaia Early Data Release 3: The Galactic anticentre

Author: Antoja, T. McMillan, P.J. Kordopatis, G. Ramos, P. Helmi, A. Balbinot, E. Cantat-Gaudin, T. Chemin, L. Figueras, F. Jordi, C. Khanna, S. Romero-Gómez, M. Seabroke, G.M. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Biermann, M. Creevey, O.L. Evans, D.W. Eyer, L. Hutton, A. Jansen, F. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Walton, N.A. Arenou, F. Bailer-Jones, C.A.L. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Van Leeuwen, F. Bakker, J. Castañeda, J. De Angeli, F. Ducourant, C. Fabricius, C. Fouesneau, M. Frémat, Y. Guerra, R. Guerrier, A. Guiraud, J. Jean-Antoine Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nicolas, C. Nienartowicz, K. Pailler, F. Panuzzo, P. Riclet, F. Roux, W. Sordo, R. Tanga, P. Thévenin, F. Gracia-Abril, G. Portell, J. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Brugaletta, E. Burgess, P.W. Busso, G. Carry, B. Cellino, A. Cheek, N. Clementini, G. Damerdji, Y. Davidson, M. Delchambre, L. Dell'Oro, A. Fernández-Hernández, J. Galluccio, L. García-Lario, P. Garcia-Reinaldos, M. González-Núñez, J. Gosset, E. Haigron, R. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hatzidimitriou, D. Heiter, U. Hernández, J. Hestroffer, D. Hodgkin, S.T. Holl, B. Janßen, K. Jevardat De Fombelle, G. Jordan, S. Krone-Martins, A. Lanzafame, A.C. Löffler, W. Lorca, A. Manteiga, M. Marchal, O. Marrese, P.M. Moitinho, A. Mora, A. Muinonen, K. Osborne, P. Pancino, E. Pauwels, T. Recio-Blanco, A. Richards, P.J. Riello, M. Rimoldini, L. Robin, A.C. Roegiers, T. Rybizki, J. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Ulla, A. Utrilla, E. Van Leeuwen, M. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Aguado, J.J. Ajaj, M. Altavilla, G. Álvarez, M.A. Álvarez Cid-Fuentes, J. Alves, J. Anderson, R.I. Varela, E.A. Audard, M. Baines, D. Baker, S.G. Balaguer-Núñez, L. Balog, Z. Barache, C. Barbato, D. Barros, M. Barstow, M.A. Bartolomé, S. Bassilana, J.-L. Bauchet, N. Baudesson-Stella, A. Becciani, U. Bellazzini, M. Bernet, M. Bertone, S. Bianchi, L. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Bossini, D. Bouquillon, S. Bragaglia, A. Bramante, L. Breedt, E. Bressan, A. Brouillet, N. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cánovas, H. Carballo, R. Carlucci, T. Carnerero, M.I. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Castro Sampol, P. Chaoul, L. Charlot, P. Chiavassa, A. Cioni, M.-R.L. Comoretto, G. Cooper, W.J. Cornez, T. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Dafonte, C. Dapergolas, A. David, M. David, P. De Laverny, P. De Luise, F. De March, R. De Ridder, J. De Souza, R. De Teodoro, P. De Torres, A. Del Peloso, E.F. Del Pozo, E. Delgado, A. Delgado, H.E. Delisle, J.-B. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Eappachen, D. Enke, H. Esquej, P. Fabre, C. Fabrizio, M. Faigler, S. Fedorets, G. Fernique, P. Fienga, A. Fouron, C. Fragkoudi, F. Fraile, E. Franke, F. Gai, M. Garabato, D. Garcia-Gutierrez, A. García-Torres, M. Garofalo, A. Gavras, P. Gerlach, E. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomez, A. Gonzalez-Santamaria, I. González-Vidal, J.J. Granvik, M. Gutiérrez-Sánchez, R. Guy, L.P. Hauser, M. Haywood, M. Hidalgo, S.L. Hilger, T. Hładczuk, N. Hobbs, D. Holland, G. Huckle, H.E. Jasniewicz, G. Jonker, P.G. Juaristi Campillo, J. Julbe, F. Karbevska, L. Kervella, P. Kochoska, A. Kontizas, M. Korn, A.J. Kostrzewa-Rutkowska, Z. Kruszyńska, K. Lambert, S. Lanza, A.F. Lasne, Y. Le Campion, J.-F. Le Fustec, Y. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Madrero Pardo, P. Managau, S. Mann, R.G. Marchant, J.M. Marconi, M. Marcos Santos, M.M.S. Marinoni, S. Marocco, F. Marshall, D.J. Martin Polo, L. Martín-Fleitas, J.M. Masip, A. Massari, D. Mastrobuono-Battisti, A. Mazeh, T. Messina, S. Michalik, D. Millar, N.R. Mints, A. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Munoz, D. Muraveva, T. Murphy, C.P. Musella, I. Noval, L. Ordénovic, C. Orrù, G. Osinde, J. Pagani, C. Pagano, I. Palaversa, L. Palicio, P.A. Panahi, A. Pawlak, M. Peñalosa Esteller, X. Penttilä, A. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poretti, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rainer, M. Raiteri, C.M. Rambaux, N. Ramos-Lerate, M. Re Fiorentin, P. Regibo, S. Reylé, C. Ripepi, V. Riva, A. Rixon, G. Robichon, N. Robin, C. Roelens, M. Rohrbasser, L. Rowell, N. Royer, F. Rybicki, K.A. Sadowski, G. Sagristà Sellés, A. Sahlmann, J. Salgado, J. Salguero, E. Samaras, N. Sanchez Gimenez, V. Sanna, N. Santoveña, R. Sarasso, M. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Semeux, D. Siddiqui, H.I. Siebert, A. Siltala, L. Slezak, E. Smart, R.L. Solano, E. Solitro, F. Souami, D. Souchay, J. Spagna, A. Spoto, F. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Süveges, M. Szabados, L. Szegedi-Elek, E. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Thuillot, W. Tonello, N. Torra, F. Torra, J. Turon, C. Unger, N. Vaillant, M. Van Dillen, E. Vanel, O. Vecchiato, A. Viala, Y. Vicente, D. Voutsinas, S. Weiler, M. Wevers, T. Wyrzykowski, L. Yoldas, A. Yvard, P. Zhao, H. Zorec, J. Zucker, S. Zurbach, C. Zwitter, T.
Subjects: Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Aims. We aim to demonstrate the scientific potential of the Gaia Early Data Release 3 (EDR3) for the study of different aspects of the Milky Way structure and evolution and we provide, at the same time, a description of several practical aspects of the data and examples of their usage. Methods. We used astrometric positions, proper motions, parallaxes, and photometry from EDR3 to select different populations and components and to calculate the distances and velocities in the direction of the anticentre. In this direction, the Gaia astrometric data alone enable the calculation of the vertical and azimuthal velocities; also, the extinction is relatively low compared to other directions in the Galactic plane. We then explore the disturbances of the current disc, the spatial and kinematical distributions of early accreted versus in situ stars, the structures in the outer parts of the disc, and the orbits of open clusters Berkeley 29 and Saurer 1. Results. With the improved astrometry and photometry of EDR3, we find that: (i) the dynamics of the Galactic disc are very complex with oscillations in the median rotation and vertical velocities as a function of radius, vertical asymmetries, and new correlations, including a bimodality with disc stars with large angular momentum moving vertically upwards from below the plane, and disc stars with slightly lower angular momentum moving preferentially downwards; (ii) we resolve the kinematic substructure (diagonal ridges) in the outer parts of the disc for the first time; (iii) the red sequence that has been associated with the proto-Galactic disc that was present at the time of the merger with Gaia-Enceladus-Sausage is currently radially concentrated up to around 14 kpc, while the blue sequence that has been associated with debris of the satellite extends beyond that; (iv) there are density structures in the outer disc, both above and below the plane, most probably related to Monoceros, the Anticentre Stream, and TriAnd, for which the Gaia data allow an exhaustive selection of candidate member stars and dynamical study; and (v) the open clusters Berkeley 29 and Saurer 1, despite being located at large distances from the Galactic centre, are on nearly circular disc-like orbits. Conclusions. Even with our simple preliminary exploration of the Gaia EDR3, we demonstrate how, once again, these data from the European Space Agency are crucial for our understanding of the different pieces of our Galaxy and their connection to its global structure and history. © ESO 2021.
Published: 2021

12. Gaia Early Data Release 3 Summary of the contents and survey properties

Author: Brown, A.G.A., Vallenari, A., Prusti, T., Bruijne, J.H.J. de, Babusiaux, C., Biermann, M., Aerts, C., Eappachen, D., Jonker, P.G., Zurbach, C., Zwitter, T., Brown, A.G.A., Vallenari, A., Prusti, T., Bruijne, J.H.J. de, Babusiaux, C., Biermann, M., Aerts, C., Eappachen, D., Jonker, P.G., Zurbach, C., and Zwitter, T.
Abstract: Contains fulltext : 233670.pdf (Publisher’s version ) (Open Access)
Published: 2021

13. Gaia Early Data Release 3. Summary of the contents and survey properties (Corrigendum)

Author: Brown, A.G.A., Vallenari, A., Prusti, T., Aerts, C., Eappachen, D., Jonker, P.G., Zucker, M.E., Zurbach, C., Zwitter, T., Brown, A.G.A., Vallenari, A., Prusti, T., Aerts, C., Eappachen, D., Jonker, P.G., Zucker, M.E., Zurbach, C., and Zwitter, T.
Abstract: Contains fulltext : 234260.pdf (Publisher’s version ) (Open Access)
Published: 2021

14. Gaia Photometric Science Alerts

Author: Hodgkin, S.T., Harrison, D.L., Breedt, E., Wevers, T., Rixon, G., Delgado, A., Yoldas, A., Kostrzewa-Rutkowska, Z., Wyrzykowski, Ł., van Leeuwen, M., Blagorodnova, N, Campbell, H., Eappachen, D., Fraser, M., Ihanec, N., Koposov, S.E., Kruszynska, K., Marton, G., Rybicki, K.A., Brown, A.G.A., Burgess, P.W., Busso, G., Cowell, S., De Angeli, F., Diener, C., Evans, D.W., Gilmore, G., Holland, G., Jonker, P.G., van Leeuwen, F., Mignard, F., Osborne, P.J., Portell, J., Prusti, T., Richards, P.J., Riello, M., Seabroke, G.M., Walton, N.A., Ábrahám, Péter, Altavilla, G., Baker, S.G., Bastian, U., O'Brien, p., de Bruijne, J., Butterley, T., Carrasco, J.M., Castañeda, J., Clark, J.S., Clementini, G., Copperwheat, C.M., Cropper, M., Damljanovic, G., Davidson, M., Davis, C.J., Dennefeld, M., Dhillon, V.S., Dolding, C., Dominik, M., Esquej, P., Eyer, L., Fabricius, C., Fridman, M., Froebrich, Dirk, Garralda, N., Gomboc, A., González-Vidal, J.J., Guerra, R., Hambly, N.C., Hardy, L.K., Holl, B., Hourihane, A., Japelj, J., Kann, D.A., Kiss, C., Knigge, C., Kolb, U., Komossa, S., Kóspál, Á., Kovács, G., Kun, M., Leto, G., Lewis, F., Littlefair, S.P., Mahabal, A.A., Mundell, C.G., Nagy, Z., Padeletti, D., Palaversa, L., Pigulski, A., Pretorius, M.L., van Reeven, W., Ribeiro, V.A.R.M., Roelens, M., Rowell, N., Schartel, N., Scholz, A., Schwope, A., Sipocz, B.M., Smartt, S.J., Smith, M.D., Serraller, I., Steeghs, D., Sullivan, M., Szabados, L., Szegedi-Elek, E., Tisserand, P., Tomasella, L., van Velzen, S., Whitelock, P.A., Wilson, R.W., Young, D.R., Hodgkin, S.T., Harrison, D.L., Breedt, E., Wevers, T., Rixon, G., Delgado, A., Yoldas, A., Kostrzewa-Rutkowska, Z., Wyrzykowski, Ł., van Leeuwen, M., Blagorodnova, N, Campbell, H., Eappachen, D., Fraser, M., Ihanec, N., Koposov, S.E., Kruszynska, K., Marton, G., Rybicki, K.A., Brown, A.G.A., Burgess, P.W., Busso, G., Cowell, S., De Angeli, F., Diener, C., Evans, D.W., Gilmore, G., Holland, G., Jonker, P.G., van Leeuwen, F., Mignard, F., Osborne, P.J., Portell, J., Prusti, T., Richards, P.J., Riello, M., Seabroke, G.M., Walton, N.A., Ábrahám, Péter, Altavilla, G., Baker, S.G., Bastian, U., O'Brien, p., de Bruijne, J., Butterley, T., Carrasco, J.M., Castañeda, J., Clark, J.S., Clementini, G., Copperwheat, C.M., Cropper, M., Damljanovic, G., Davidson, M., Davis, C.J., Dennefeld, M., Dhillon, V.S., Dolding, C., Dominik, M., Esquej, P., Eyer, L., Fabricius, C., Fridman, M., Froebrich, Dirk, Garralda, N., Gomboc, A., González-Vidal, J.J., Guerra, R., Hambly, N.C., Hardy, L.K., Holl, B., Hourihane, A., Japelj, J., Kann, D.A., Kiss, C., Knigge, C., Kolb, U., Komossa, S., Kóspál, Á., Kovács, G., Kun, M., Leto, G., Lewis, F., Littlefair, S.P., Mahabal, A.A., Mundell, C.G., Nagy, Z., Padeletti, D., Palaversa, L., Pigulski, A., Pretorius, M.L., van Reeven, W., Ribeiro, V.A.R.M., Roelens, M., Rowell, N., Schartel, N., Scholz, A., Schwope, A., Sipocz, B.M., Smartt, S.J., Smith, M.D., Serraller, I., Steeghs, D., Sullivan, M., Szabados, L., Szegedi-Elek, E., Tisserand, P., Tomasella, L., van Velzen, S., Whitelock, P.A., Wilson, R.W., and Young, D.R.
Abstract: Context. Since July 2014, the Gaia mission has been engaged in a high-spatial-resolution, time-resolved, precise, accurate astrometric, and photometric survey of the entire sky. Aims. We present the Gaia Science Alerts project, which has been in operation since 1 June 2016. We describe the system which has been developed to enable the discovery and publication of transient photometric events as seen by Gaia. Methods. We outline the data handling, timings, and performances, and we describe the transient detection algorithms and filtering procedures needed to manage the high false alarm rate. We identify two classes of events: (1) sources which are new to Gaiaand (2) Gaia sources which have undergone a significant brightening or fading. Validation of the Gaia transit astrometry and photometry was performed, followed by testing of the source environment to minimise contamination from Solar System objects, bright stars, and fainter near-neighbours. Results. We show that the Gaia Science Alerts project suffers from very low contamination, that is there are very few false-positives. We find that the external completeness for supernovae, CE = 0.46, is dominated by the Gaia scanning law and the requirement of detections from both fields-of-view. Where we have two or more scans the internal completeness is CI = 0.79 at 3 arcsec or larger from the centres of galaxies, but it drops closer in, especially within 1 arcsec. Conclusions. The per-transit photometry for Gaia transients is precise to 1 per cent at G = 13, and 3 per cent at G = 19. The per-transit astrometry is accurate to 55 milliarcseconds when compared to Gaia DR2. The Gaia Science Alerts project is one of the most homogeneous and productive transient surveys in operation, and it is the only survey which covers the whole sky at high spatial resolution (subarcsecond), including the Galactic plane and bulge.
Published: 2021

15. Chasing the Galactic structure using VLBI and Gaia

Author: Quiroga-Nunez, L.H., Langevelde, H.J. van, Reid, M., Sjouwerman, L., Pihlstrom, Y., Lewis, M., Brown, A.G.A., Tirimba, K., Kapinska, A., and Kapinska, A.
Published: 2020

16. Gaia DR2 in the making

Author: Lammers, U., Brown, A.G.A., Gracia, G., Ballester, P., Ibsen, J., Solar, M., Shortridge, K., Ballester, P., Ibsen, J., Solar, M., and Shortridge, K.
Published: 2020

17. Erratum: Gaia Data Release 2: The kinematics of globular clusters and dwarf galaxies around the Milky Way (Astronomy and Astrophysics (2018) 616 (A12) DOI: 10.1051/0004-6361/201832698)

Author: Helmi, A. Van Leeuwen, F. McMillan, P.J. Massari, D. Antoja, T. Robin, A.C. Lindegren, L. Bastian, U. Arenou, F. Babusiaux, C. Biermann, M. Breddels, M.A. Hobbs, D. Jordi, C. Pancino, E. Reylé, C. Veljanoski, J. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Evans, D.W. Eyer, L. Jansen, F. Klioner, S.A. Lammers, U. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Walton, N.A. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. Garciá-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. Garciá-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Heu, J. Hilger, T. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Matijevič, G. Mazeh, T. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: This is a corrigendum to Gaia Collaboration (2018). It corrects errors in Appendix B, which describes the modelling of the Large and Small Magellanic Clouds (LMC and SMC). One of these errors also affects Fig. 18 of the paper, which shows the rotation curve and median radial motion in the LMC. No other results in the paper are affected. There should be no vector products in Appendix B, and everywhere a vector product appears should be a scalar product. This affects Eqs. (B.5), (B.8), (B.10), (B.12), (B.13), and (B.20). Equation (B.10), which defines one component of position within the plane of the galaxy, contains an additional typographical error, and it should have read (Farmula Presented) Equation (B.21) is incorrect. The factor of (ax + by + z) is applied to the wrong part of the equation. It should have read (Farmula Presented) This error affects the derived deprojected motions of stars in the LMC, and means that changes in the observational signature of the bulk motion away from the centre are not properly accounted for. The effect becomes more significant further from the centre. Figure 1 shows the resulting median tangential velocity, vT (the rotation curve), and median radial velocity vR as a function of de-projected radius R for the LMC, which is otherwise produced in the same way as before. The major differences between this and the equivalent figure in Gaia Collaboration (2018) are as follows The rotation curve reaches a greater velocity (~85 km s-1 versus ~75 km s-1) and remains flat beyond 6 kpc, as opposed to starting to fall. The difference in asymmetric drift for the blue and red populations is clearer the blue population, which is typically younger than the redder population, is rotating faster. The apparent outward motion of the stellar populations is much smaller. The blue population has almost no net radial motion, while the red population has one of .8 km s-1 (as opposed to ~20 km s-1). The difference in radial motion between the y < 0 and y > 0 populations is dramatically reduced, as is the difference between the value derived assuming the known line-of-sight bulk motion and the one derived leaving this value free. © 2020 ESO.
Published: 2020

18. Erratum: Gaia Data Release 2: Kinematics of globular clusters and dwarf galaxies around the Milky Way (A&A (2018) 616 (A12) DOI: 10.1051/0004-6361/201832698)

Author: Helmi, A. Van Leeuwen, F. McMillan, P.J. Massari, D. Antoja, T. Robin, A.C. Lindegren, L. Bastian, U. Arenou, F. Babusiaux, C. Biermann, M. Breddels, M.A. Hobbs, D. Jordi, C. Pancino, E. Reylé, C. Veljanoski, J. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Evans, D.W. Eyer, L. Jansen, F. Klioner, S.A. Lammers, U. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Walton, N.A. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Delloro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Heu, J. Hilger, T. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Matijevič, G. Mazeh, T. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevems, T. Wyrzykowski, Ł. Yoldas, A. Erjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T. Helmi, A.
Abstract: An error occurred during the production process of the original published version. The following names were omitted from the author list: R. Haigron, D. Hatzidimitriou, M. Hauser, M. Haywood, U. Heiter, J. Heu, T. Hilger. The original published version has been corrected together with the publication of this corrigendum. © 2020 EDP Sciences. All rights reserved.
Published: 2020

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

Author: Eyer, L. Rimoldini, L. Audard, M. Anderson, R.I. Nienartowicz, K. Glass, F. Marchal, O. Grenon, M. Mowlavi, N. Holl, B. Clementini, G. Aerts, C. Mazeh, T. Evans, D.W. Szabados, L. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Bailer-Jones, C.A.L. Biermann, M. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Masana, E. Messineo, R. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, A.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Lorenz, D. Managau, S. Mann, R.G. Mantelet, G. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijevič, G. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, A. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Subjects: Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G â‰² 21 mag. Aims. We showcase stellar variability in the Galactic colour-absolute magnitude diagram (CaMD). We focus on pulsating, eruptive, and cataclysmic variables, as well as on stars that exhibit variability that is due to rotation and eclipses. Methods. We describe the locations of variable star classes, variable object fractions, and typical variability amplitudes throughout the CaMD and show how variability-related changes in colour and brightness induce "motions". To do this, we use 22 months of calibrated photometric, spectro-photometric, and astrometric Gaia data of stars with a significant parallax. To ensure that a large variety of variable star classes populate the CaMD, we crossmatched Gaia sources with known variable stars. We also used the statistics and variability detection modules of the Gaia variability pipeline. Corrections for interstellar extinction are not implemented in this article. Results. Gaia enables the first investigation of Galactic variable star populations in the CaMD on a similar, if not larger, scale as was previously done in the Magellanic Clouds. Although the observed colours are not corrected for reddening, distinct regions are visible in which variable stars occur. We determine variable star fractions to within the current detection thresholds of Gaia. Finally, we report the most complete description of variability-induced motion within the CaMD to date. Conclusions. Gaia enables novel insights into variability phenomena for an unprecedented number of stars, which will benefit the understanding of stellar astrophysics. The CaMD of Galactic variable stars provides crucial information on physical origins of variability in a way that has previously only been accessible for Galactic star clusters or external galaxies. Future Gaia data releases will enable significant improvements over this preview by providing longer time series, more accurate astrometry, and additional data types (time series BP and RP spectra, RVS spectra, and radial velocities), all for much larger samples of stars. © 2019 ESO.
Published: 2019

20. All-Sky Near Infrared Space Astrometry

Author: Hobbs, D., Leitz, C., Bartlett, J., Hepburn, I., Kawata, D., Cropper, M., Mazin, B., Brown, A.G.A., Makarov, V., McArthur, B., Moore, A., Sharp, R., Gilbert, J., and Høg, E.
Published: 2019

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

Author: Brown, A.G.A., Aerts, C., Jonker, P.G., Nelemans, G.A., and Wevers, T.
Subjects: Astronomy, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries)
Abstract: Contains fulltext : 162635.pdf (Publisher’s version ) (Closed access)
Published: 2016

22. Astrometric surveys: Solving the Milky Way puzzle with Gaia

Author: Brown A.G.A.
Subjects: Physics, QC1-999
Abstract: In this contribution I provide a brief summary of ongoing and future astrometric surveys and then focus on presenting the current status and expected scientific performance of the Gaia mission, scheduled for launch in 2013.
Published: 2012
Full Text: View/download PDF

23. Observational hertzsprung-russell diagrams

Author: Babusiaux, C. Van Leeuwen, F. Barstow, M.A. Jordi, C. Vallenari, A. Bossini, D. Bressan, A. Cantat-Gaudin, T. Van Leeuwen, M. Brown, A.G.A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Subjects: Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, and homogeneity of both astrometry and photometry are unprecedented. Aims. We highlight the power of the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell diagram (HRD). Gaia allows us to present many different HRDs, depending in particular on stellar population selections. We do not aim here for completeness in terms of types of stars or stellar evolutionary aspects. Instead, we have chosen several illustrative examples. Methods. We describe some of the selections that can be made in Gaia DR2 to highlight the main structures of the Gaia HRDs. We select both field and cluster (open and globular) stars, compare the observations with previous classifications and with stellar evolutionary tracks, and we present variations of the Gaia HRD with age, metallicity, and kinematics. Late stages of stellar evolution such as hot subdwarfs, post-AGB stars, planetary nebulae, and white dwarfs are also analysed, as well as low-mass brown dwarf objects. Results. The Gaia HRDs are unprecedented in both precision and coverage of the various Milky Way stellar populations and stellar evolutionary phases. Many fine structures of the HRDs are presented. The clear split of the white dwarf sequence into hydrogen and helium white dwarfs is presented for the first time in an HRD. The relation between kinematics and the HRD is nicely illustrated. Two different populations in a classical kinematic selection of the halo are unambiguously identified in the HRD. Membership and mean parameters for a selected list of open clusters are provided. They allow drawing very detailed cluster sequences, highlighting fine structures, and providing extremely precise empirical isochrones that will lead to more insight in stellar physics. Conclusions. Gaia DR2 demonstrates the potential of combining precise astrometry and photometry for large samples for studies in stellar evolution and stellar population and opens an entire new area for HRD-based studies. © ESO 2018.
Published: 2018

24. Observations of solar system objects

Author: Spoto, F. Tanga, P. Mignard, F. Berthier, J. Carry, B. Cellino, A. Dell'Oro, A. Hestroffer, D. Muinonen, K. Pauwels, T. Petit, J.-M. David, P. De Angeli, F. Delbo, M. Frézouls, B. Galluccio, L. Granvik, M. Guiraud, J. Hernández, J. Ordénovic, C. Portell, J. Poujoulet, E. Thuillot, W. Walmsley, G. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Bailer-Jones, C.A.L. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Riello, M. Seabroke, G.M. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Blomme, R. Burgess, P. Busso, G. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Osinde, J. Pancino, E. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, M. De Laverny, P. De Luise, F. De March, R. De Souza, R. De Torres, A. Debosscher, J. De Pozo, E.L. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Gueguen, A. Guerrier, A. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: Context. The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Data Release 2 (DR2) contains the observations of a selected sample of 14,099 SSOs. These asteroids have been already identified and have been numbered by the Minor Planet Center repository. Positions are provided for each Gaia observation at CCD level. As additional information, complementary to astrometry, the apparent brightness of SSOs in the unfiltered G band is also provided for selected observations. Aims. We explain the processing of SSO data, and describe the criteria we used to select the sample published in Gaia DR2. We then explore the data set to assess its quality. Methods. To exploit the main data product for the solar system in Gaia DR2, which is the epoch astrometry of asteroids, it is necessary to take into account the unusual properties of the uncertainty, as the position information is nearly one-dimensional. When this aspect is handled appropriately, an orbit fit can be obtained with post-fit residuals that are overall consistent with the a-priori error model that was used to define individual values of the astrometric uncertainty. The role of both random and systematic errors is described. The distribution of residuals allowed us to identify possible contaminants in the data set (such as stars). Photometry in the G band was compared to computed values from reference asteroid shapes and to the flux registered at the corresponding epochs by the red and blue photometers (RP and BP). Results. The overall astrometric performance is close to the expectations, with an optimal range of brightness G ∼ 12 - 17. In this range, the typical transit-level accuracy is well below 1 mas. For fainter asteroids, the growing photon noise deteriorates the performance. Asteroids brighter than G ∼ 12 are affected by a lower performance of the processing of their signals. The dramatic improvement brought by Gaia DR2 astrometry of SSOs is demonstrated by comparisons to the archive data and by preliminary tests on the detection of subtle non-gravitational effects. © ESO 2018.
Published: 2018

25. Maser, infrared and optical emission for late-type stars in the Galactic plane

Author: Quiroga-Nuñez, L.H., Langevelde, H.J. van, Sjouwerman, L.O., Pihlström, Y.M., Reid, M.J., Brown, A.G.A., Green, J.A., Tarchi, A., Reid, M., and Castangia, P.
Subjects: Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, law.invention, law, Bulge, Very-long-baseline interferometry, Astrophysics::Solar and Stellar Astrophysics, Maser, education, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, education.field_of_study, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Astrometry, Galactic plane, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics
Abstract: Radio astrometric campaigns using VLBI have provided distances and proper motions for masers associated with young massive stars (BeSSeL survey). The ongoing BAaDE project plans to obtain astrometric information of SiO maser stars located in the inner Galaxy. These stars are associated with evolved, mass-losing stars. By overlapping optical (Gaia), infrared (2MASS, MSX and WISE) and radio (BAaDE) sources, we expect to obtain important clues on the intrinsic properties and population distribution of late-type stars. Moreover, a comparison of the Galactic parameters obtained with Gaia and VLBI can be done using radio observations on different targets: young massive stars (BeSSeL) and evolved stars (BAaDE)., Comment: To appear in the Proceedings of the IAU Symposium No. 336: Astrophysical Masers: Unlocking the Mysteries of the Universe
Published: 2018

26. Summary of the contents and survey properties

Author: Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Babusiaux, C. Bailer-Jones, C.A.L. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Abstract: Context. We present the second Gaia data release, Gaia DR2, consisting of astrometry, photometry, radial velocities, and information on astrophysical parameters and variability, for sources brighter than magnitude 21. In addition epoch astrometry and photometry are provided for a modest sample of minor planets in the solar system. Aims. A summary of the contents of Gaia DR2 is presented, accompanied by a discussion on the differences with respect to Gaia DR1 and an overview of the main limitations which are still present in the survey. Recommendations are made on the responsible use of Gaia DR2 results. Methods. The raw data collected with the Gaia instruments during the first 22 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into this second data release, which represents a major advance with respect to Gaia DR1 in terms of completeness, performance, and richness of the data products. Results. Gaia DR2 contains celestial positions and the apparent brightness in G for approximately 1.7 billion sources. For 1.3 billion of those sources, parallaxes and proper motions are in addition available. The sample of sources for which variability information is provided is expanded to 0.5 million stars. This data release contains four new elements: broad-band colour information in the form of the apparent brightness in the GBP (330-680 nm) and GRP (630-1050 nm) bands is available for 1.4 billion sources; median radial velocities for some 7 million sources are presented; for between 77 and 161 million sources estimates are provided of the stellar effective temperature, extinction, reddening, and radius and luminosity; and for a pre-selected list of 14 000 minor planets in the solar system epoch astrometry and photometry are presented. Finally, Gaia DR2 also represents a new materialisation of the celestial reference frame in the optical, the Gaia-CRF2, which is the first optical reference frame based solely on extragalactic sources. There are notable changes in the photometric system and the catalogue source list with respect to Gaia DR1, and we stress the need to consider the two data releases as independent. Conclusions. Gaia DR2 represents a major achievement for the Gaia mission, delivering on the long standing promise to provide parallaxes and proper motions for over 1 billion stars, and representing a first step in the availability of complementary radial velocity and source astrophysical information for a sample of stars in the Gaia survey which covers a very substantial fraction of the volume of our galaxy. © ESO 2018.
Published: 2018

27. Gaia Data Release 2: The celestial reference frame (Gaia -CRF2)

Author: Mignard, F. Klioner, S.A. Lindegren, L. Hernández, J. Bastian, U. Bombrun, A. Hobbs, D. Lammers, U. Michalik, D. Ramos-Lerate, M. Biermann, M. Fernández-Hernández, J. Geyer, R. Hilger, T. Siddiqui, H.I. Steidelmüller, H. Babusiaux, C. Barache, C. Lambert, S. Andrei, A.H. Bourda, G. Charlot, P. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Luri, X. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Soubiran, C. Van Leeuwen, F. Walton, N.A. Arenou, F. Cropper, M. Drimmel, R. Katz, D. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Anglada Varela, E. Antiche, E. Antoja, T. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Borrachero, R. Bossini, D. Bouquillon, S. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypers, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. DIakite, S. DIener, C. DIstefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. Jevardat De Fombelle, G. Jonker, P.G. Juhász, A.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poggio, E. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Regibo, S. Reylé, C. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, L. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Subjects: Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context. The second release of Gaia data (Gaia DR2) contains the astrometric parameters for more than half a million quasars. This set defines a kinematically non-rotating reference frame in the optical domain. A subset of these quasars have accurate VLBI positions that allow the axes of the reference frame to be aligned with the International Celestial Reference System (ICRF) radio frame. Aims. We describe the astrometric and photometric properties of the quasars that were selected to represent the celestial reference frame of Gaia DR2 (Gaia-CRF2), and to compare the optical and radio positions for sources with accurate VLBI positions. Methods. Descriptive statistics are used to characterise the overall properties of the quasar sample. Residual rotation and orientation errors and large-scale systematics are quantified by means of expansions in vector spherical harmonics. Positional differences are calculated relative to a prototype version of the forthcoming ICRF3. Results. Gaia-CRF2 consists of the positions of a sample of 556 869 sources in Gaia DR2, obtained from a positional cross-match with the ICRF3-prototype and AllWISE AGN catalogues. The sample constitutes a clean, dense, and homogeneous set of extragalactic point sources in the magnitude range G ≈ 16 to 21 mag with accurately known optical positions. The median positional uncertainty is 0.12 mas for G < 18 mag and 0.5 mas at G = mag. Large-scale systematics are estimated to be in the range 20 to 30 μas. The accuracy claims are supported by the parallaxes and proper motions of the quasars in Gaia DR2. The optical positions for a subset of 2820 sources in common with the ICRF3-prototype show very good overall agreement with the radio positions, but several tens of sources have significantly discrepant positions. Conclusions. Based on less than 40% of the data expected from the nominal Gaia mission, Gaia-CRF2 is the first realisation of a non-rotating global optical reference frame that meets the ICRS prescriptions, meaning that it is built only on extragalactic sources. Its accuracy matches the current radio frame of the ICRF, but the density of sources in all parts of the sky is much higher, except along the Galactic equator. © ESO 2018.
Published: 2018

28. Mapping the milky way disc kinematics

Author: Katz, D. Antoja, T. Romero-Gómez, M. Drimmel, R. Reylé, C. Seabroke, G.M. Soubiran, C. Babusiaux, C. Di Matteo, P. Figueras, F. Poggio, E. Robin, A.C. Evans, D.W. Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Bailer-Jones, C.A.L. Biermann, M. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Van Leeuwen, F. Walton, N.A. Arenou, F. Bastian, U. Cropper, M. Lattanzi, M.G. Bakker, J. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Holl, B. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Panuzzo, P. Portell, J. Riello, M. Tanga, P. Thévenin, F. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Teyssier, D. Altmann, M. Andrae, R. Audard, M. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Burgess, P. Busso, G. Carry, B. Cellino, A. Clementini, G. Clotet, M. Creevey, O. Davidson, M. De Ridder, J. Delchambre, L. Dell'Oro, A. Ducourant, C. Fernández-Hernández, J. Fouesneau, M. Frémat, Y. Galluccio, L. García-Torres, M. González-Núñez, J. González-Vidal, J.J. Gosset, E. Guy, L.P. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hernández, J. Hestroffer, D. Hodgkin, S.T. Hutton, A. Jasniewicz, G. Jean-Antoine-Piccolo, A. Jordan, S. Korn, A.J. Krone-Martins, A. Lanzafame, A.C. Lebzelter, T. Löffler, W. Manteiga, M. Marrese, P.M. Martín-Fleitas, J.M. Moitinho, A. Mora, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Richards, P.J. Rimoldini, L. Sarro, L.M. Siopis, C. Smith, M. Sozzetti, A. Süveges, M. Torra, J. Van Reeven, W. Abbas, U. Abreu Aramburu, A. Accart, S. Aerts, C. Altavilla, G. Álvarez, M.A. Alvarez, R. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Arcay, B. Astraatmadja, T.L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Balm, P. Barache, C. Barata, C. Barbato, D. Barblan, F. Barklem, P.S. Barrado, D. Barros, M. Barstow, M.A. Bartholomé Muñoz, S. Bassilana, J.-L. Becciani, U. Bellazzini, M. Berihuete, A. Bertone, S. Bianchi, L. Bienaymé, O. Blanco-Cuaresma, S. Boch, T. Boeche, C. Bombrun, A. Borrachero, R. Bossini, D. Bouquillon, S. Bourda, G. Bragaglia, A. Bramante, L. Breddels, M.A. Bressan, A. Brouillet, N. Brüsemeister, T. Brugaletta, E. Bucciarelli, B. Burlacu, A. Busonero, D. Butkevich, A.G. Buzzi, R. Caffau, E. Cancelliere, R. Cannizzaro, G. Cantat-Gaudin, T. Carballo, R. Carlucci, T. Carrasco, J.M. Casamiquela, L. Castellani, M. Castro-Ginard, A. Charlot, P. Chemin, L. Chiavassa, A. Cocozza, G. Costigan, G. Cowell, S. Crifo, F. Crosta, M. Crowley, C. Cuypersy, J. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Laverny, P. De Luise, F. De March, R. De Souza, R. De Torres, A. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Diakite, S. Diener, C. Distefano, E. Dolding, C. Drazinos, P. Durán, J. Edvardsson, B. Enke, H. Eriksson, K. Esquej, P. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernique, P. Filippi, F. Findeisen, K. Fonti, A. Fraile, E. Fraser, M. Frézouls, B. Gai, M. Galleti, S. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavel, A. Gavras, P. Gerssen, J. Geyer, R. Giacobbe, P. Gilmore, G. Girona, S. Giuffrida, G. Glass, F. Gomes, M. Granvik, M. Gueguen, A. Guerrier, A. Guiraud, J. Gutiérrez-Sánchez, R. Haigron, R. Hatzidimitriou, D. Hauser, M. Haywood, M. Heiter, U. Helmi, A. Heu, J. Hilger, T. Hobbs, D. Hofmann, W. Holland, G. Huckle, H.E. Hypki, A. Icardi, V. Janßen, K. De Fombelle, G.J. Jonker, P.G. Juhász, Á.L. Julbe, F. Karampelas, A. Kewley, A. Klar, J. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, M. Kontizas, E. Koposov, S.E. Kordopatis, G. Kostrzewa-Rutkowska, Z. Koubsky, P. Lambert, S. Lanza, A.F. Lasne, Y. Lavigne, J.-B. Le Fustec, Y. Le Poncin-Lafitte, C. Lebreton, Y. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. López, M. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marschalkó, G. Marshall, D.J. Martino, M. Marton, G. Mary, N. Massari, D. Matijević, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Molina, D. Molinaro, R. Molnár, L. Montegriffo, P. Mor, R. Morbidelli, R. Morel, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Nelemans, G. Nicastro, L. Noval, L. O'Mullane, W. Ordénovic, C. Ordóñez-Blanco, D. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Panahi, A. Pawlak, M. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Racero, E. Ragaini, S. Rambaux, N. Ramos-Lerate, M. Regibo, S. Riclet, F. Ripepi, V. Riva, A. Rivard, A. Rixon, G. Roegiers, T. Roelens, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sanna, N. Santana-Ros, T. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Ségransan, D. Shih, I.-C. Siltala, L. Silva, A.F. Smart, R.L. Smith, K.W. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Teyssandier, P. Thuillot, W. Titarenko, A. Torra Clotet, F. Turon, C. Ulla, A. Utrilla, E. Uzzi, S. Vaillant, M. Valentini, G. Valette, V. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Vaschetto, M. Vecchiato, A. Veljanoski, J. Viala, Y. Vicente, D. Vogt, S. Von Essen, C. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Wertz, O. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Ziaeepour, H. Zorec, J. Zschocke, S. Zucker, S. Zurbach, C. Zwitter, T.
Subjects: Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Context. The second Gaia data release (Gaia DR2) contains high-precision positions, parallaxes, and proper motions for 1.3 billion sources as well as line-of-sight velocities for 7.2 million stars brighter than GRVS = 12 mag. Both samples provide a full sky coverage. Aims. To illustrate the potential of Gaia DR2, we provide a first look at the kinematics of the Milky Way disc, within a radius of several kiloparsecs around the Sun. Methods. We benefit for the first time from a sample of 6.4 million F-G-K stars with full 6D phase-space coordinates, precise parallaxes (σω/ω/≤ 20%), and precise Galactic cylindrical velocities (median uncertainties of 0.9-1.4 km s-1 and 20% of the stars with uncertainties smaller than 1 km s-1 on all three components). From this sample, we extracted a sub-sample of 3.2 million giant stars to map the velocity field of the Galactic disc from ∼5 kpc to ∼13 kpc from the Galactic centre and up to 2 kpc above and below the plane. We also study the distribution of 0.3 million solar neighbourhood stars (r < 200 pc), with median velocity uncertainties of 0.4 km s-1, in velocity space and use the full sample to examine how the over-densities evolve in more distant regions. Results. Gaia DR2 allows us to draw 3D maps of the Galactocentric median velocities and velocity dispersions with unprecedented accuracy, precision, and spatial resolution. The maps show the complexity and richness of the velocity field of the galactic disc. We observe streaming motions in all the components of the velocities as well as patterns in the velocity dispersions. For example, we confirm the previously reported negative and positive galactocentric radial velocity gradients in the inner and outer disc, respectively. Here, we see them as part of a non-axisymmetric kinematic oscillation, and we map its azimuthal and vertical behaviour. We also witness a new global arrangement of stars in the velocity plane of the solar neighbourhood and in distant regions in which stars are organised in thin substructures with the shape of circular arches that are oriented approximately along the horizontal direction in the U - V plane. Moreover, in distant regions, we see variations in the velocity substructures more clearly than ever before, in particular, variations in the velocity of the Hercules stream. Conclusions. Gaia DR2 provides the largest existing full 6D phase-space coordinates catalogue. It also vastly increases the number of available distances and transverse velocities with respect to Gaia DR1. Gaia DR2 offers a great wealth of information on the Milky Way and reveals clear non-axisymmetric kinematic signatures within the Galactic disc, for instance. It is now up to the astronomical community to explore its full potential. © ESO 2018.
Published: 2018

29. Hypervelocity star candidates in Gaia DR1/TGAS

Author: Marchetti, T., Rossi, E.M., Kordopatis, G., Brown, A.G.A., Rimoldi, A., Starkenburg, E., Youakim, K., Ashley, R., Recio-Blanco, A., Laverny, P. de, Brown, A., Prusti, T., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Recio-Blanco, A., Laverny, P. de, Brown, A., and Prusti, T.
Subjects: Physics, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, Astrometry, Star (graph theory), 01 natural sciences, Space and Planetary Science, 0103 physical sciences, Hypervelocity, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Hypervelocity stars (HVSs) are characterized by a total velocity in excess of the Galactic escape speed, and with trajectories consistent with coming from the Galactic Centre. We apply a novel data mining routine, an artificial neural network, to discover HVSs in the TGAS subset of the first data release of the Gaia satellite, using only the astrometry of the stars. We find 80 stars with a predicted probability >90% of being HVSs, and we retrieved radial velocities for 47 of those. We discover 14 objects with a total velocity in the Galactic rest frame >400 km s−1, and 5 of these have a probability >50% of being unbound from the Milky Way. Tracing back orbits in different Galactic potentials, we discover 1 HVS candidate, 5 bound HVS candidates, and 5 runaway star candidates with remarkably high velocities, between 400 and 780 km s−1. We wait for future Gaia releases to confirm the goodness of our sample and to increase the number of HVS candidates.
Published: 2018

30. Mapping young stellar populations towards Orion with Gaia DR1

Author: Zari, E.M., Brown, A.G.A., Recio-Blanco, A., Laverny, P. de, Brown, A., and Prusti, T.
Subjects: Physics, Space and Planetary Science, Astronomy and Astrophysics
Abstract: OB associations are prime sites for the study of star formation processes and of the interaction between young massive stars with the interstellar medium. Furthermore, the kinematics and structure of the nearest OB associations provide detailed insight into the properties and origin of the Gould Belt. In this context, the Orion complex has been extensively studied. However, the spatial distribution of the stellar population is still uncertain: in particular, the distances and ages of the various sub-groups composing the Orion OB association, and their connection to the surrounding interstellar medium, are not well determined. We used the first Gaia data release to characterize the stellar population in Orion, with the goal to obtain new distance and age estimates of the numerous stellar groups composing the Orion OB association. We found evidence of the existence of a young and rich population spread over the entire region, loosely clustered around some known groups. This newly discovered population of young stars provides a fresh view of the star formation history of the Orion region.
Published: 2018

31. Gaia Data Release 2. Summary of the contents and survey properties

Author: Brown, A.G.A., Vallenari, A., Prusti, T., Bruijne, J.H.J. de, Babusiaux, C., Bailer-Jones, C.A.L., Bakker, Joost, Jordan, S., Aerts, C., Bossini, D., Cannizzaro, G., Jonker, P.G., Nelemans, G., Silva, A., Wevers, T., Zurbach, C., Zwitter, T., Brown, A.G.A., Vallenari, A., Prusti, T., Bruijne, J.H.J. de, Babusiaux, C., Bailer-Jones, C.A.L., Bakker, Joost, Jordan, S., Aerts, C., Bossini, D., Cannizzaro, G., Jonker, P.G., Nelemans, G., Silva, A., Wevers, T., Zurbach, C., and Zwitter, T.
Abstract: Contains fulltext : 194726.pdf (publisher's version ) (Open Access)
Published: 2018

32. The Gaia sky: version 1.0

Author: Brown, A.G.A., Recio-Blanco, A., Laverny, P. de, Brown, A., and Prusti, T.
Subjects: Systematic error, 010504 meteorology & atmospheric sciences, Computer science, media_common.quotation_subject, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrometry, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Sky, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Look-ahead, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, media_common
Abstract: In this contribution I provide a brief summary of the contents of Gaia DR1. This is followed by a discussion of studies in the literature that attempt to characterize the quality of the Tycho-Gaia Astrometric Solution parallaxes in Gaia DR1, and I point out a misconception about the handling of the known systematic errors in the Gaia DR1 parallaxes. I highlight some of the more unexpected uses of the Gaia DR1 data and close with a look ahead at the next Gaia data releases, with Gaia DR2 coming up in April 2018., 10 pages, 1 figure, to appear in Proceedings of IAU Symposium 330 "Astrometry and Astrophysics in the Gaia Sky", slightly edited version, updated references
Published: 2017

33. Gaia Data Release 1: Testing parallaxes with local Cepheids and RR Lyrae stars

Author: Clementini, G. Eyer, L. Ripepi, V. Marconi, M. Muraveva, T. Garofalo, A. Sarro, L.M. Palmer, M. Luri, X. Molinaro, R. Rimoldini, L. Szabados, L. Musella, I. Anderson, R.I. Prusti, T. De Bruijne, J.H.J. Brown, A.G.A. Vallenari, A. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Drimmel, R. Høg, E. Katz, D. Lattanzi, M.G. O'Mullane, W. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Perryman, M. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Barrado, N.Y. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Durán, J. Dzigan, Y. Edvardsson, B. Enke, H. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Krone-Martins, A. Kudryashova, M. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lorenz, D. Macdonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Reylé, C. Ribeiro, R.A. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Shih, I.-C. Smareglia, R. Smart, R.L. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Wevers, T. Wyrzykowski, L. Yoldas, A. Zerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. Lebouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. O'Flaherty, K.S. Ocvirk, P. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'Homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. StraizYs, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Abstract: 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). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σΩ/Ω< 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with σΩ/Ω< 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with σΩ/Ω< 0.5). The new relations were computed using multi-band (V,I,J,Ks) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and MV- [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. © ESO, 2017.
Published: 2017

34. The Gaia mission

Author: Prusti, T. De Bruijne, J.H.J. Brown, A.G.A. Vallenari, A. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Milligan, D.J. Panem, C. Poinsignon, V. Pourbaix, D. Randich, S. Sarri, G. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Drimmel, R. Høg, E. Katz, D. Lattanzi, M.G. O'Mullane, W. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Clementini, G. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Atzei, A. Ayache, L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Baroni, M. Barrado Y Navascués, D. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bellei, G. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bouy, H. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Budnik, F. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Charvet, P. Chassat, F. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Collins, P. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Marco, F. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Durán, J. Dzigan, Y. Ecale, E. Edvardsson, B. Enke, H. Erdmann, M. Escolar, D. Espina, M. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Faye, F. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Furnell, R. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garé, P. Garofalo, A. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Kowalczyk, A. Krone-Martins, A. Kudryashova, M. Kull, I. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lopez-Lozano, A. Lorenz, D. Loureiro, T. MacDonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marie, J. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Mestre, A. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, R. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Monteiro, D. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morley, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Paulsen, T. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pereira, J. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Renk, F. Reylé, C. Ribeiro, R.A. Rimoldini, L. Ripepi, V. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Rudolph, A. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schnorhk, A. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Serpell, E. Shih, I.-C. Smareglia, R. Smart, R.L. Smith, C. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Werner, D. Wevers, T. Whitehead, G. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. Lebouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. Ocvirk, P. O'Flaherty, K.S. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Palmer, M. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Sembay, S. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. Straižys, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Subjects: instruments [space vehicles], proper motions, parallaxes, astrometry, telescopes, structure [Galaxy]
Abstract: Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page.http://www.cosmos.esa.int/gaia
Published: 2016

35. Prospects for detection of detached double white dwarf binaries with Gaia, LSST and LISA

Author: Korol, V., Rossi, E.M., Groot, P.J., Nelemans, G.A., Toonen, S., Brown, A.G.A., Korol, V., Rossi, E.M., Groot, P.J., Nelemans, G.A., Toonen, S., and Brown, A.G.A.
Abstract: Contains fulltext : 176424pre.pdf (preprint version ) (Closed access) Contains fulltext : 176424pub.pdf (publisher's version ) (Open Access)
Published: 2017

36. The Gaia mission

Author: Prusti, T., De Bruijne, J.H.J., Brown, A.G.A., Vallenari, A., Babusiaux, C., Bailer-Jones, C.A.L., Bastian, U., Biermann, M., Evans, D.W., Eyer, L., Jansen, F., Jordi, C., Klioner, S.A., Lammers, U., Lindegren, L., Luri, X., Mignard, F., Milligan, D.J., Panem, C., Poinsignon, V., Pourbaix, D., Randich, S., Sarri, G., Sartoretti, P., Siddiqui, H.I., Soubiran, C., Valette, V., Van Leeuwen, F., Walton, N.A., Aerts, C., Arenou, F., Cropper, M., Drimmel, R., Høg, E., Katz, D., Lattanzi, M.G., O'Mullane, W., Grebel, E.K., Holland, A.D., González-Marcos, Ana., and A. Bello García
Subjects: instruments [Space vehicles], Parallaxes, Astrometry, Proper motions, structure [Galaxy], Telescopes
Abstract: Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page. © ESO, 2016.
Published: 2016

37. Gaia archive

Author: Hypki, A.P., Brown, A.G.A., Rozanska A., Bejger M., and Rozanska A., Bejger M.
Published: 2016

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

Author: Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Mignard, F. Drimmel, R. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Katz, D. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. O'Mullane, W. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Høg, E. Lattanzi, M.G. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Perryman, M. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Clementini, G. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Barrado Y Navascués, D. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bouy, H. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Duran, J. Dzigan, Y. Edvardsson, B. Enke, H. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Krone-Martins, A. Kudryashova, M. Kull, I. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lorenz, D. MacDonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, R. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Reylé, C. Ribeiro, R.A. Rimoldini, L. Ripepi, V. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Shih, I.-C. Smareglia, R. Smart, R.L. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. LeBouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. Ocvirk, P. O'Flaherty, K.S. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Palmer, M. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Sembay, S. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. Straižys, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Abstract: 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 illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr-1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr-1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data. © ESO, 2016.
Published: 2016

39. Astrometric Galactic maser measurements cross-matched with Gaia

Author: Quiroga-Nuñez, L.H., Langevelde, H.J.van, Reid, M.J., Sjouwerman, L.O., Pihlström, Y.M., Brown, A.G.A., Green, J.A., Chiappini, C., Minchev, I., Starkenburg, E., and Valentini, M.
Subjects: Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, symbols.namesake, law, Bulge, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Maser, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, education.field_of_study, 010308 nuclear & particles physics, Astronomy, Astronomy and Astrophysics, Astrometry, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), symbols, Astrophysics::Earth and Planetary Astrophysics, Bessel function
Abstract: Using the VLBA, the BeSSeL survey has provided distances and proper motions of young massive stars, allowing an accurate measure of the Galactic spiral structure. By the same technique, we are planning to map the inner Galaxy using positions and velocities of evolved stars (provided by the BAaDE survey). These radio astrometric measurements (BeSSeL and BAaDE) will be complementary to Gaia results and the overlap will provide important clues on the intrinsic properties and population distribution of the stars in the bulge., To appear in the Proceedings of the IAU Symposium No. 334: "Rediscovering our Galaxy"
Published: 2017

40. Dynamics of the Oort Cloud In the Gaia Era I: Close Encounters

Author: Torres Rodriguez, S., Portegies Zwart, S.F., Brown, A.G.A., Recio-Blanco, A., Laverny, de P., Brown, A., Prusti, T., Recio-Blanco, A., Laverny, de P., Brown, A., and Prusti, T.
Subjects: Physics, Solar System, 010504 meteorology & atmospheric sciences, business.industry, Astronomy and Astrophysics, Cloud computing, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrobiology, Space and Planetary Science, Dynamics (music), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: Comets in the Oort cloud evolve under the influence of internal and external perturbations from giant planets to stellar passages, the Galactic tides, and the interstellar medium.Using the positions, parallaxes and proper motions from TGAS in Gaia DR1 and combining them with the radial velocities from the RAVE-DR5, Geneva-Copenhagen and Pulkovo catalogues, we calculated the closest encounters the Sun has had with other stars in the recent past and will have in the near future. We find that the stars with high proper motions near to the present time are missing in the Gaia-TGAS, and those to tend to be the closest ones. The quality of the data allows putting better constraints on the encounter parameters, compared to previous surveys.
Published: 2017

41. GREAT-ITN and Gaia: Preparing for Science

Author: WALTON, N.A., BAILER-JONES, C.A.L., BROWN, A.G.A., CLEMENTINI, G., EYER, L., FELTZING, S., FIGUERAS, F., GREBEL, E.K., MICHALOWSKI, T., RIDDER, J. De, SANTOS, N., SMITH, M.C., SOUBIRAN, C., BALAGUER-NÚÑEZ, L., Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Geneva Observatory, University of Geneva [Switzerland], Lund Observatory, Lund University [Lund], Universitat de Barcelona (UB), Adam Mickiewicz University in Poznań (UAM), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Departamento de Física e Astronomia [Porto] (DFA/FCUP), Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto-Universidade do Porto, National Optical Astronomy Observatory, M2A 2015, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), and Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Engineering management, Initial training, 010308 nuclear & particles physics, Space and Planetary Science, 0103 physical sciences, General Engineering, Astronomy and Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Engineering physics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract: International audience; his paper gives a brief overview of the Gaia Research for European Astronomy Training (GREAT) network, including a description of the GREAT-ESF Research Network Programme and the GREAT Initial Training Network (GREAT-ITN). Scientific highlights from the GREAT-ITN are noted.
Published: 2014

42. Halo white dwarfs in the Gaia era

Author: Oirschot, P. van, Nelemans, G.A., Pols, O.R., Helmi, A., Tolsoy, E., Brown, A.G.A., Pugliese, G., and Pugliese, G.
Subjects: Astronomy, Astronomical Society of the Pacific Conference Series
Abstract: Item does not contain fulltext
Published: 2013

43. High precision astrometry mission for the detection and characterization of nearby habitable planetary systems with the Nearby Earth Astrometric Telescope (NEAT)

Author: Malbet, F., Leger, A., Shao, M., Goullioud, R., Lagage, P.O., Brown, A.G.A., Cara, C., Durand, G., Eiroa, C., Feautrier, P., Jakobsson, B., Hinglais, E., Kaltenegger, L., Lababie, L., Lagrange, A.M., Laskar, J., Liseau, R., Lunine, J., Maldonado, J., Mercier, M., Mordasini, C., Queloz, D., Quirrenb, A., Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2012

44. Summary of BP/RP pre-processing in PhotPipe

Author: Brown, A.G.A., Busso, G., MARRESE, Paola Maria, DE LUISE, Fiore, Giuffrida, Giuliano, PIERSIMONI, Anna Marina, Pulone, Luigi, CASTELLANI, Marco, Risquez, Daniel, ITA, and van Leeuwen Floor
Abstract: Nota tecnica interna alla partecipazione alla missione ESA/Gaia , soggetta ad embargo This document provides a top-level description of the CU5-DU11 algorithms for BP/RP image pre-processing within PhotPipe.
Published: 2012

45. Binary white dwarfs in the halo of the Milky Way

Author: Oirschot, P. van, Nelemans, G.A., Toonen, S., Pols, O., Brown, A.G.A., Helmi, A., Zwart, S.P., Oirschot, P. van, Nelemans, G.A., Toonen, S., Pols, O., Brown, A.G.A., Helmi, A., and Zwart, S.P.
Abstract: Contains fulltext : 132465.pdf (preprint version ) (Open Access)
Published: 2014

46. Gaia on-board metrology: basic angle and best focus

Author: Mora, A., Biermann, M., Brown, A.G.A., Busonero, D., Carminati, L., Carrasco, J.M., Chassat, F., Erdmann, M., Gielesen, W.L.M., Jordi, C., Katz, D., Kohley, R., Lindegren, L., Loeffler, W., Marchal, O., Panuzzo, P., Seabroke, G., Sahlmann, J., Serpell, E., Serraller, I., Leeuwen, F. van, Reeven, W. van, Dool, T.C. van den, Vosteen, L.L.A., Mora, A., Biermann, M., Brown, A.G.A., Busonero, D., Carminati, L., Carrasco, J.M., Chassat, F., Erdmann, M., Gielesen, W.L.M., Jordi, C., Katz, D., Kohley, R., Lindegren, L., Loeffler, W., Marchal, O., Panuzzo, P., Seabroke, G., Sahlmann, J., Serpell, E., Serraller, I., Leeuwen, F. van, Reeven, W. van, Dool, T.C. van den, and Vosteen, L.L.A.
Abstract: The Gaia payload ensures maximum passive stability using a single material, SiC, for most of its elements. Dedicated metrology instruments are, however, required to carry out two functions: monitoring the basic angle and refocusing the telescope. Two interferometers fed by the same laser are used to measure the basic angle changes at the level of μas (prad, micropixel), which is the highest level ever achieved in space. Two Shack- Hartmann wavefront sensors, combined with an ad-hoc analysis of the scientific data are used to define and reach the overall best-focus. In this contribution, the systems, data analysis, procedures and performance achieved during commissioning are presented. © 2014 SPIE.
Published: 2014

47. The Gaia Archive.

Author: Mora, Alcione, González-Núñez, Juan, Baines, Deborah, Durán, Javier, Gutiérrez-Sanchéz, Raúl, Racero, Elena, Salgado, Jesús, Segovia, Juan Carlos, Recio-Blanco, A., de Laverny, P., Brown, A.G.A., and Prusti, T.
Abstract: The Archive is the main Gaia data distribution hub. The contents of DR1 are briefly reviewed and the data structures discussed. The system architecture, based on Virtual Observatory standards, is also presented, together with the extensions that allow e.g. authenticated access, persistent uploads and table sharing. Finally some usage examples are provided. [ABSTRACT FROM PUBLISHER]
Published: 2017
Full Text: View/download PDF

48. Optical interferometry and Gaia parallaxes for a robust calibration of the Cepheid distance scale.

Author: Kervella, Pierre, Mérand, Antoine, Gallenne, Alexandre, Trahin, Boris, Borgniet, Simon, Pietrzynski, Grzegorz, Nardetto, Nicolas, Gieren, Wolfgang, Recio-Blanco, A., de Laverny, P., Brown, A.G.A., and Prusti, T.
Abstract: We present the modeling tool we developed to incorporate multi-technique observations of Cepheids in a single pulsation model: the Spectro-Photo-Interferometry of Pulsating Stars (SPIPS). The combination of angular diameters from optical interferometry, radial velocities and photometry with the coming Gaia DR2 parallaxes of nearby Galactic Cepheids will soon enable us to calibrate the projection factor of the classical Parallax-of-Pulsation method. This will extend its applicability to Cepheids too distant for accurate Gaia parallax measurements, and allow us to precisely calibrate the Leavitt law's zero point. As an example application, we present the SPIPS model of the long-period Cepheid RS Pup that provides a measurement of its projection factor, using the independent distance estimated from its light echoes. [ABSTRACT FROM PUBLISHER]
Published: 2017
Full Text: View/download PDF

49. Self-consistent modelling of our Galaxy with Gaia data.

Author: Binney, James, Recio-Blanco, A., de Laverny, P., Brown, A.G.A., and Prusti, T.
Abstract: Galaxy models are fundamental to exploiting surveys of our Galaxy. There is now a significant body of work on axisymmetric models. A model can be defined by giving the DF of each major class of stars and of dark matter. Then the self-consistent gravitational potential is determined. Other modelling techniques are briefly considered before an overview of some early work on non-axisymmetric models. [ABSTRACT FROM PUBLISHER]
Published: 2017
Full Text: View/download PDF

50. Tribute to François Mignard's research.

Author: Kovalevsky, Jean, Recio-Blanco, A., de Laverny, P., Brown, A.G.A., and Prusti, T.
Abstract: It is a great pleasure for me to report about your colleague and my friend François Mignard. I know him since now 43 years and shared with him some scientific adventures. If, because of my age, I had to leave the Gaia project, I have followed the tremendous work done since by François Mignard and noticed that, despite his masterly played role as the conductor of the Gaia orchestra, he kept an important scientific activity. Actually, Gaia is far from being all his scientific achievements. And this is what I shall try to convince you. [ABSTRACT FROM PUBLISHER]
Published: 2017
Full Text: View/download PDF

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