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1. THE QUEST FOR DISCOVERING EXTRAGALACTIC CEPHEIDS

Author: Laszlo Szabados
Subjects: Astronomy, QB1-991
Abstract: Chronology of studying extragalactic Cepheids is summarized, and the census of known classical Cepheids and their metal-deficient siblings, the anomalous Cepheids is taken. Up to now (August 2005) about 11000 Cepheids have been revealed in 74 galaxies. Cepheids belonging to the Milky Way galaxy only represent about 6 percent of the total Cepheid sample.
Published: 2017
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2. The impact of the absence of aliphatic glucosinolates on insect herbivory in Arabidopsis.

Author: Jules Beekwilder, Wessel van Leeuwen, Nicole M van Dam, Monica Bertossi, Valentina Grandi, Luca Mizzi, Mikhail Soloviev, Laszlo Szabados, Jos W Molthoff, Bert Schipper, Hans Verbocht, Ric C H de Vos, Piero Morandini, Mark G M Aarts, and Arnaud Bovy
Subjects: Medicine, Science
Abstract: Aliphatic glucosinolates are compounds which occur in high concentrations in Arabidopsis thaliana and other Brassicaceae species. They are important for the resistance of the plant to pest insects. Previously, the biosynthesis of these compounds was shown to be regulated by transcription factors MYB28 and MYB29. We now show that MYB28 and MYB29 are partially redundant, but in the absence of both, the synthesis of all aliphatic glucosinolates is blocked. Untargeted and targeted biochemical analyses of leaf metabolites showed that differences between single and double knock-out mutants and wild type plants were restricted to glucosinolates. Biosynthesis of long-chain aliphatic glucosinolates was blocked by the myb28 mutation, while short-chain aliphatic glucosinolates were reduced by about 50% in both the myb28 and the myb29 single mutants. Most remarkably, all aliphatic glucosinolates were completely absent in the double mutant. Expression of glucosinolate biosynthetic genes was slightly but significantly reduced by the single myb mutations, while the double mutation resulted in a drastic decrease in expression of these genes. Since the myb28myb29 double mutant is the first Arabidopsis genotype without any aliphatic glucosinolates, we used it to establish the relevance of aliphatic glucosinolate biosynthesis to herbivory by larvae of the lepidopteran insect Mamestra brassicae. Plant damage correlated inversely to the levels of aliphatic glucosinolates observed in those plants: Larval weight gain was 2.6 fold higher on the double myb28myb29 mutant completely lacking aliphatic glucosinolates and 1.8 higher on the single mutants with intermediate levels of aliphatic glucosinolates compared to wild type plants.
Published: 2008
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3. Gaia Early Data Release 3 The Gaia Catalogue of Nearby Stars

Author: Zoltan Balog, G. Tauran, Vincenzo Ripepi, Gerry Gilmore, M. Barros, Łukasz Wyrzykowski, Alberto Cellino, E. Poggio, P. Gavras, Simchon Faigler, Marc Audard, C. Nicolas, M. Vaillant, A. Mora, Paolo Tanga, Silvio Leccia, Despina Hatzidimitriou, A. Dapergolas, Eva Sciacca, Alberto Krone-Martins, N. Cheek, M. Hauser, Ulrike Heiter, S. Managau, L. Rohrbasser, Mathias Schultheis, E. Utrilla, Minia Manteiga, Marcella Marconi, Xavier Luri, F. De Angeli, Shay Zucker, Paolo Giacobbe, J. Juaristi Campillo, H. I. Siddiqui, J. Torra, F. X. Pineau, Roy Gomel, Thierry Morel, T. Cornez, Eric Gosset, Mario Gai, Jose M Hernandez, G. Giuffrida, A. de Torres, Laszlo Szabados, S. Ragaini, E. van Dillen, D. Semeux, Leanne P. Guy, R. Drimmel, L. M. Sarro, S. Voutsinas, Johannes Sahlmann, Damien Ségransan, S. Liao, Derek W. Morris, Jan Rybizki, André Moitinho, T. Roegiers, Bengt Edvardsson, Tristan Cantat-Gaudin, Martin Altmann, C. Turon, Laurent Chemin, K. Janßen, D. Garabato, Alejandra Recio-Blanco, Michał Pawlak, Lorenzo Rimoldini, Sergei A. Klioner, F. Torra, Carine Babusiaux, Alfred Castro-Ginard, G. Plum, Mariateresa Crosta, Iain A. Steele, A. Yoldas, Alex Lobel, J.-L. Bassilana, Harry Enke, Rosanna Sordo, Francesca Fragkoudi, F. De Luise, M. Bernet, Alessandro Sozzetti, M. Kontizas, Roberto Molinaro, C. Diener, S. Regibo, D. Barbato, T. Pauwels, R. E. de Souza, C. Fabricius, D. Souami, L. Martin Polo, M. Ramos-Lerate, Douglas J. Marshall, A. G. Butkevich, P. Madrero Pardo, P. Re Fiorentin, J. F. Le Campion, Jérôme Berthier, N. Tonello, Ummi Abbas, Y. Lebreton, M. Biermann, D. Munoz, N. Brouillet, David Teyssier, O. Vanel, P. A. Palicio, A. Jean-Antoine Piccolo, A. F. Lanza, Jesus Salgado, E. del Pozo, Antti Penttilä, R. Geyer, Ramachrisna Teixeira, L. Chaoul, Mike Smith, Rossella Cancelliere, J. M. Martín-Fleitas, D. Baines, M. Romero-Gómez, E. Anglada Varela, E. Livanou, X. Peñalosa Esteller, S. Diakite, Alberto Vecchiato, Thomas Wevers, Daniel Hestroffer, Sebastian L. Hidalgo, M. David, Angela Bragaglia, J. De Ridder, Mark Taylor, Roberto Morbidelli, A. Sagristà Sellés, Nigel Hambly, Arnaud Siebert, R. L. Smart, P. Burgess, Y. Le Fustec, Alessandro Bressan, H. Steidelmüller, Alberto Riva, H. E. Huckle, Morgan Fouesneau, N. Bauchet, P. Osborne, S. Marinoni, Krzysztof A. Rybicki, A. Masip, Laia Casamiquela, R. Messineo, A. Garofalo, Antonella Vallenari, R. Mor, Sahar Shahaf, P. de Laverny, G. Sadowski, Peter G. Jonker, A. Kochoska, F. Taris, A. F. Mulone, M. Ajaj, C. Ducourant, T. A. Lister, F. A. Jansen, Ruth Carballo, J. M. Carrasco, Tatiana Muraveva, W. van Reeven, P. Sartoretti, Jordi Portell, Andreas Korn, E. Salguero, Ana Ulla, P. Di Matteo, Coryn A. L. Bailer-Jones, J. Bakker, F. Riclet, G. Altavilla, Ulrich Bastian, P. Esquej, R. Buzzi, M. Segol, A. C. Lanzafame, L. Balaguer-Núñez, Beatrice Bucciarelli, C. Panem, E. Balbinot, T. Carlucci, Davide Massari, P. de Teodoro, Sébastien Lambert, M. I. Carnerero, Amina Helmi, F. Solitro, C. Robin, Carlos Dafonte, Tsevi Mazeh, A. Panahi, C. Fabre, Sergi Blanco-Cuaresma, Deborah Busonero, Maroussia Roelens, O. Marchal, Tomaz Zwitter, B. Holl, G. Holland, William Thuillot, Michael Davidson, E. Licata, Michele Bellazzini, Teresa Antoja, E. Szegedi-Elek, Francesca Figueras, Eric Slezak, Sergio Messina, N. Samaras, E. Poujoulet, Mark Cropper, A. Burlacu, R. Blomme, Elmé Breedt, Annie C. Robin, H. E. Delgado, Z. Kostrzewa-Rutkowska, Georges Kordopatis, Conny Aerts, L. Noval, Daniel Michalik, P. J. Richards, L. Karbevska, Grigori Fedorets, Maria Süveges, F. Crifo, J. Guiraud, D. Eappachen, K. Kruszyńska, Gisella Clementini, P. Yvard, Carme Jordi, L. Bramante, G. Busso, P. David, E. Fraile, Ugo Becciani, A. Lorca, Sanjeev Khanna, Alex Bombrun, Isabella Pagano, C. Dolding, A. M. Piersimoni, Paolo Montegriffo, A. Abreu Aramburu, Anthony G. A. Brown, Simon Hodgkin, Ennio Poretti, M. Fabrizio, I. Gonzalez-Santamaria, N. A. Walton, P. Panuzzo, Benoit Carry, Raphael Guerra, J. J. González-Vidal, T. Lebzelter, Nami Mowlavi, C. Barache, M. M. S. Marcos Santos, S. Cowell, Marco Castellani, J. J. Aguado, N. R. Millar, A. Baudesson-Stella, N. Leclerc, S. Bartolomé, J. Álvarez Cid-Fuentes, F. van Leeuwen, S. Bouquillon, Uwe Lammers, D. W. Evans, L. Eyer, M. van Leeuwen, A. Guerrier, J. González-Núñez, H. E. P. Lindstrøm, Miguel García-Torres, Ilaria Musella, L. Palaversa, W. Roux, W. Löffler, J.-B. Delisle, Dimitri Pourbaix, Timo Prusti, J. Osinde, M. Riello, G. Orrù, C. Crowley, Alessandra Mastrobuono-Battisti, Hector Canovas, D. L. Harrison, Y. Lasne, E. F. del Peloso, Laurent Galluccio, N. Hładczuk, T. Boch, Martin A. Barstow, László Molnár, Aldo Dell'Oro, C. Pagani, Krzysztof Nienartowicz, Stefano Bertone, Patrick Charlot, Eduard Masana, Elisabetta Caffau, N. Robichon, Luciana Bianchi, Federica Spoto, Felix Franke, J. L. Halbwachs, R. Gutiérrez-Sánchez, L. Pulone, Yassine Damerdji, Frédéric Arenou, Richard I. Anderson, Elena Pancino, David Hobbs, P. Castro Sampol, Yves Fremat, Pierre Kervella, C. Zurbach, Sofia Randich, Robert G. Mann, J. C. Segovia, Diego Bossini, D. Katz, Nicholas Rowell, P. Ramos, E. Racero, G. Gracia-Abril, R. Santoveña, R. Haigron, N. Unger, Enrique Solano, S. G. Baker, W. J. Cooper, F. Royer, S. Accart, George M. Seabroke, João Alves, Emese Plachy, Thomas Hilger, Pedro García-Lario, Gérard Jasniewicz, Kevin Benson, Christos Siopis, J. Souchay, Agnes Fienga, Giovanni Comoretto, F. Julbe, A. Hutton, Pierre Fernique, Céline Reylé, F. Pailler, Stefan Jordan, J. H. J. de Bruijne, C. A. Stephenson, E. Gerlach, Elisa Distefano, Karri Muinonen, Y. Viala, H. Zhao, L. Siltala, C. P. Murphy, Maria-Rosa L. Cioni, Andrea Chiavassa, D. Molina, J. Fernández-Hernández, G. Jevardat de Fombelle, Federico Marocco, Nicoletta Sanna, Alexey Mints, Juan Zorec, Ángel Gómez, I. Bellas-Velidis, M. G. Lattanzi, C. M. Raiteri, E. Brugaletta, Mikael Granvik, O. L. Creevey, Guy Rixon, Francois Mignard, P. M. Marrese, M. A. Álvarez, Caroline Soubiran, Rene Andrae, C. Ordénovic, A. Delgado, V. Sanchez Gimenez, J. Castañeda, D. Vicente, R. De March, A. Garcia-Gutierrez, M. Weiler, F. Thévenin, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Jon Marchant, Monica Rainer, Alessandro Spagna, Andrej Prsa, M. Sarasso, Nicolas Rambaux, Paul J. McMillan, Ludovic Delchambre, M. Garcia-Reinaldos, M. Haywood, C. Fouron, S. Girona, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Universidad de Barcelona, Xunta de Galicia, Generalitat de Catalunya, INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Astronomische Rechen-Institut [Heidelberg] (ARI), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg]-Universität Heidelberg [Heidelberg], Systèmes de Référence Temps Espace (SYRTE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Mésocentre de calcul (MESOCENTRE), Université de Franche-Comté (UFC), Centre de Données Astronomiques de Strasbourg, Partenaires INRAE, Géoazur (GEOAZUR 7329), Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - 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CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University-Universität Heidelberg [Heidelberg] = Heidelberg University, Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), THALES [France], 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), 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Universidad de Cantabria, Gaia Collaboration, Planetary-system research, Department of Physics, Particle Physics and Astrophysics, Astronomy, and ITA
Subjects: trigonometric parallaxes, Solar neighborhood, Stars: luminosity function, mass function, Astronomy, Astrophysics, 01 natural sciences, luminosity function, mass function [Stars], Astronomi, astrofysik och kosmologi, luminosity: mass function [Stars], Astronomy, Astrophysics and Cosmology, MAIN-SEQUENCE, Hertzsprung-Russell-diagram, 010303 astronomy & astrophysics, Stars:low-mass brown-dwarfs, wide binaries, Physics, education.field_of_study, north galactic pole, Astrophysics::Instrumentation and Methods for Astrophysics, Astrometry, BROWN DWARF, Astrophysics - Solar and Stellar Astrophysics, mass function, NORTH GALACTIC POLE, Physical Sciences, symbols, CIRCULAR-VELOCITY CURVE, Halo, astro-ph.SR, Hertzsprung–Russell diagram, stars: luminosity function, astro-ph.GA, Posterior probability, Population, main-sequence, Luminosity-Function, FOS: Physical sciences, Mass-Function, Astronomy & Astrophysics, Computer Science::Digital Libraries, Photometry (optics), DWARF LUMINOSITY-FUNCTION, dwarf luminosity-function, sky-survey, symbols.namesake, Settore FIS/05 - Astronomia e Astrofisica, luminosity function [stars], low-mass [Stars], 0103 physical sciences, Stars: luminosity: mass function, Stars: low-mass, WHITE-DWARFS, education, Solar and Stellar Astrophysics (astro-ph.SR), brown dwarf, catalogs, astrometry, Hertzsprung-Russell and C-M diagrams, stars: low-mass, solar neighborhood, Astrophysics - Astrophysics of Galaxies, SKY-SURVEY, white-dwarfs, Science & Technology, 010308 nuclear & particles physics, Luminosity function, White dwarf, TRIGONOMETRIC PARALLAXES, Astronomy and Astrophysics, Low-mass, 115 Astronomy, Space science, WIDE BINARIES, Stars, Physics::History of Physics, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), solar-neighborhood, Catalogs, circular-velocity curve, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
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.
Published: 2021
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4. Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE

Author: M. Schuil, G. Zins, Y. Fantei, Udo Beckmann, Péter Ábrahám, Anthony Meilland, K. Shabun, Philippe Stee, Farrokh Vakili, Ronald Roelfsema, A. Böhm, Andrea Chiavassa, G. Niccolini, L. Labadie, L. Mosoni, M. Riquelme, Alexandre Gallenne, P. Antonelli, R. Frahm, J.-L. Lizon, Markus Schöller, Ralf-Rainer Rohloff, Florentin Millour, Jean-Michel Clausse, Udo Neumann, F. Wrhel, M. de Haan, J. Meisner, Leonard Burtscher, R. Huerta, F. Allouche, Luca Pasquini, E. Garces, Pierre Cruzalèbes, Nicolas Nardetto, S. Morel, Behnam Javanmardi, P. Bourget, L. Jochum, A. Ridinger, R. S. Le Poole, Th. Rivinius, Bruno Lopez, V. Hocdé, Marco Delbo, I. Percheron, P. Girard, J. C. González Herrera, M. Accardo, G. Bazin, Karl Heinz Hofmann, Laszlo Szabados, J. W. Isbell, Eric Pantin, Jaime Alonso, Josef Hron, D. Schertl, Eszter Pozna, L. Klarmann, Th. Henning, S. Rousseau, C. Connot, E. Nußbaum, Eddy Elswijk, Louise Breuval, Antoine Mérand, R. van Boekel, E. Kokoulina, Leander Mehrgan, József Varga, Roberto Abuter, Markus Wittkowski, T. Adler, E. Lagadec, Claudia Paladini, M. Heininger, F. Guitton, Nicolas Schuhler, W. Laun, Romain Petrov, A. Jaskó, S. Abadie, R. ter Horst, Stephane Lagarde, R. Brast, F. Y. J. Gonté, Norbert Hubin, William C. Danchi, V. Gámez Rosas, A. Soulain, Walter Jaffe, Pierre Kervella, W. Boland, Ramón Navarro, Michiel R. Hogerheijde, Julien Woillez, K. Meixner, Felix Bettonvil, S. Borgniet, J. Beltran, Uwe Graser, Ph. Berio, Ralf Klein, J. Idserda, M. Lopez, Klaus Meisenheimer, Andreas Glindemann, J.-U. Pott, H. Hanenburg, Lars Venema, Sylvie Robbe-Dubois, Alexis Matter, Tibor Agócs, R. Buter, M. Ebert, Carsten Dominik, P. Guajardo, Laurent Pallanca, A. Marcotto, R. Waters, A. Gabasch, R. Castillo, M. Lehmitz, Jean-Charles Augereau, Derek Ives, Yves Bresson, S. Kuindersma, A. Glazenborg, Claudia Cid, C. Stephan, Sebastian Wolf, L. Mohr, J. Kragt, Christoph Leinert, F. Rigal, N. Tromp, Xavier Haubois, N. Mauclert, Gerd Jakob, Gerd Weigelt, J. Vinther, A. Chelli, C. Bailet, Paul Bristow, A. Domiciano de Souza, T. Maurer, A. van Duin, Ralf Conzelmann, M. Mellein, G. Kroes, G. Yoffe, T. Phan Duc, 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Lagrange, Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS., European Southern Observatory (ESO), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Radioastronomie (MPIFR), Max Planck Institute for Astronomy (MPIA), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Low Energy Astrophysics (API, FNWI)
Subjects: Infrared, Cepheid variable, Astronomy, Astrophysics - astrophysics of galaxies, Flux, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - solar and stellar astrophysics, 010309 optics, Spitzer Space Telescope, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Research Programm of Institute for Mathematics, Astrophysics and Particle Physics, Stars: variables: Cepheids, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Circumstellar matter, Infrared: stars, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Stars, Wavelength, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Instrumentation: interferometers, Astrophysics of Galaxies (astro-ph.GA), Stars: atmospheres, Astrophysics::Earth and Planetary Astrophysics
Abstract: The nature of circumstellar envelopes (CSE) around Cepheids is still a matter of debate. The physical origin of their infrared (IR) excess could be either a shell of ionized gas, or a dust envelope, or both. This study aims at constraining the geometry and the IR excess of the environment of the long-period Cepheid $\ell$ Car (P=35.5 days) at mid-IR wavelengths to understand its physical nature. We first use photometric observations in various bands and Spitzer Space Telescope spectroscopy to constrain the IR excess of $\ell$ Car. Then, we analyze the VLTI/MATISSE measurements at a specific phase of observation, in order to determine the flux contribution, the size and shape of the environment of the star in the L band. We finally test the hypothesis of a shell of ionized gas in order to model the IR excess. We report the first detection in the L band of a centro-symmetric extended emission around l Car, of about 1.7$R_\star$ in FWHM, producing an excess of about 7.0\% in this band. In the N band, there is no clear evidence for dust emission from VLTI/MATISSE correlated flux and Spitzer data. On the other side, the modeled shell of ionized gas implies a more compact CSE ($1.13\pm0.02\,R_\star$) and fainter (IR excess of 1\% in the L band). We provide new evidences for a compact CSE of $\ell$ Car and we demonstrate the capabilities of VLTI/MATISSE for determining common properties of CSEs. While the compact CSE of $\ell$ Car is probably of gaseous nature, the tested model of a shell of ionized gas is not able to simultaneously reproduce the IR excess and the interferometric observations. Further Galactic Cepheids observations with VLTI/MATISSE are necessary for determining the properties of CSEs, which may also depend on both the pulsation period and the evolutionary state of the stars., Comment: 13 pages, 8 figures, accepted in Astronomy and Astrophysics
Published: 2021
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5. Symmetries in Stellar, Galactic, and Extragalactic Astronomy

Author: Laszlo Szabados
Published: 2021
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6. Gaia Early Data Release 3: Gaia photometric science alerts

Author: Gerry Gilmore, F. De Angeli, David Alexander Kann, Richard Wilson, Danny Steeghs, Cs. Kiss, Łukasz Wyrzykowski, S. Komossa, L. Palaversa, Ulrich Kolb, S. van Velzen, L. Tomasella, L. Eyer, Ágnes Kóspál, Axel Schwope, A. Yoldas, D. Padeletti, G. Kovács, N. Schartel, Christopher J. Davis, Laszlo Szabados, M. L. Pretorius, M. Fridman, J. M. Carrasco, D. L. Harrison, N. Blagorodnova, A. Hourihane, W. van Reeven, Morgan Fraser, P. Tisserand, D. W. Evans, G. Holland, P. J. Richards, K. Kruszyńska, Nicholas Rowell, Z. Nagy, Elmé Breedt, J. H. J. de Bruijne, Sergey E. Koposov, Mária Kun, M. van Leeuwen, Timothy Butterley, Christian Knigge, G. Busso, F. van Leeuwen, Martin Dominik, A. Gomboc, J. Castañeda, S. J. Smartt, J. Japelj, N. Ihanec, Simon Hodgkin, N. Garralda, Carole Mundell, A. A. Mahabal, S. G. Baker, S. P. Littlefair, J. S. Clark, P. T. O'Brien, Michael Davidson, Brigitta Sipőcz, Maroussia Roelens, Gisella Clementini, Thomas Wevers, Alexander Scholz, Giuseppe Leto, Peter G. Jonker, A. Delgado, P. Ábrahám, B. Holl, George M. Seabroke, Gábor Marton, N. A. Walton, C. Diener, G. Altavilla, Patricia A. Whitelock, Valério A. R. M. Ribeiro, Goran Damljanović, P. Burgess, D. R. Young, M. Riello, P. Osborne, Claus Fabricius, Nigel Hambly, Michael D. Smith, Mark Sullivan, D. Eappachen, A. G. A. Brown, Krzysztof A. Rybicki, H. Campbell, Raphael Guerra, Timo Prusti, J. J. González-Vidal, I. Serraller, Andrzej Pigulski, Fraser Lewis, Dirk Froebrich, V. S. Dhillon, Mark Cropper, Z. Kostrzewa-Rutkowska, Chris M. Copperwheat, Jordi Portell, Ulrich Bastian, L. K. Hardy, Michel Dennefeld, P. Esquej, E. Szegedi-Elek, Guy Rixon, Francois Mignard, C. Dolding, S. Cowell, Science and Technology Facilities Council (UK), European Research Council, European Commission, Slovenian Research Agency, Leverhulme Trust, Agenzia Spaziale Italiana, Ministry of Education, Science and Technological Development (Serbia), Netherlands Organization for Scientific Research, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science
Subjects: media_common.quotation_subject, Astronomy, Stars: variables: general, general [Supernovae], Supernovae: general, Astrophysics, Surveys, 7. Clean energy, variables: general [Stars], Variables, variable: general [Stars], QB Astronomy, General, Quasars, QC, QB, media_common, Physics, Kiss, Astronomy and Astrophysics, general [Quasars], 3rd-DAS, Creative commons, Stars, Quasars: general, QC Physics, Supernovae, 13. Climate action, Space and Planetary Science, Instrumentation and Methods for Astrophysics, Astronomical instrumentation, methods and techniques, Humanities, Data release
Abstract: Full list of authors: 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.; Kruszyńska, 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, P.; 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, D.; 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.; Sipőcz, 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.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., 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 Gaia and (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% at G = 13, and 3% at G = 19. The per-Transit astrometry is accurate to 55 mas 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. © S. T. Hodgkin et al. 2021., This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. Further details of funding authorities and individuals contributing to the success of the mission is shown at https://gea.esac.esa.int/archive/documentation/GEDR3/Miscellaneous/sec_acknowl/. We thank the United Kingdom Particle Physics and Astronomy Research Council (PPARC), the United Kingdom Science and Technology Facilities Council (STFC), and the United Kingdom Space Agency (UKSA) through the following grants to the University of Bristol, the University of Cambridge, the University of Edinburgh, the University of Leicester, the Mullard Space Sciences Laboratory of University College London, and the United Kingdom Rutherford Appleton Laboratory (RAL): PP/D006511/1, PP/D006546/1, PP/D006570/1, ST/I000852/1, ST/J005045/1, ST/K00056X/1, ST/K000209/1, ST/K000756/1, ST/L006561/1, ST/N000595/1, ST/S000623/1, ST/N000641/1, ST/N000978/1, ST/N001117/1, ST/S000089/1, ST/S000976/1, ST/S001123/1, ST/S001948/1, ST/S002103/1, and ST/V000969/1. This paper made use of the Whole Sky Database (WSDB) created by Sergey Koposov and maintained at the Institute of Astronomy, Cambridge with financial support from the Science and Technology Facilities Council (STFC) and the European Research Council (ERC). We thank the William Herschel and Isaac Newton Telescopes on the Roque de los Muchachos Observatory, La Palma, Spain, as well as the Optical Infrared Coordination Network for Astronomy (OPTICON) for their support of this project through telescope time, especially during the commissioning and verification phases. We thank the Copernico 1.82 m telescope (Mt. Ekar, Asiago Italy) operated by INAF Padova for supporting the project through telescope time (under the Large Programme Tomasella-SNe) during the verification phases. We acknowledge observations taken as part of the PESSTO project collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 199.D-0143. Authors at the ICCUB were supported by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ’María de Maeztu’) through grant CEX2019-000918-M. This work is supported by Polish NCN grants: Daina No. 2017/27/L/ST9/03221, Harmonia No. 2018/30/M/ST9/00311, Preludium No. 2017/25/N/ST9/01253 and MNiSW grant DIR/WK/2018/12 as well as the European Commission’s Horizon2020 OPTICON grant No. 730890. The Authors would like to thank the Warsaw University OGLE project for their continuous support in this work. AB acknowledges financial support from the Netherlands Research School for Astronomy (NOVA). AG acknowledges the financial support from the Slovenian Research Agency (grants P1-0031, I0-0033, J1-8136, J1-2460). AH was funded in part by the Leverhulme Trust through grant RPG-2012-541 and by the European Research Council grant 320360. AP acknowledges support from the NCN grant no. 2016/21/B/ST9/01126. CM acknowledges support from Jim and Hiroko Sherwin. DAK acknowledges support from the Spanish research projects AYA 2014-58381-P, AYA2017-89384-P, from Juan de la Cierva Incorporación fellowship IJCI-2015-26153, and from Spanish National Research Project RTI2018-098104-J-I00 (GRBPhot). EB and STH are funded by the Science and Technology Facilities Council grant ST/S000623/1. TW was funded in part by European Research Council grant 320360 and by European Commission grant 730980. GC acknowledges the Agenzia Spaziale Italiana (ASI) for its continuing support through contract 2018-24-HH.0 to the Italian Istituto Nazionale di Astrofisica (INAF). GD acknowledges the observing grant support from the Institute of Astronomy and Rozhen NAO BAS through the bilateral joint research project “Gaia Celestial Reference Frame (CRF) and fast variable astronomical objects” (during 2020-2022, leader is G. Damljanovic), and support by the Ministry of Education, Science and Technological Development of the Republic of Serbia (contract no. 451-03-68/2020-14/200002). G. Marton acknowledges support from the EC Horizon 2020 project OPTICON (730890) and the ESA PRODEX contract no. 4000129910. MF is supported by a Royal Society - Science Foundation Ireland University Research Fellowship NB acknowledges support from the research programme VENI, with project number 016.192.277, which is (partly) financed by the Netherlands Organisation for Scientific Research (NWO). NI is partially supported by Polish NCN DAINA grant no. 2017/27/L/ST9/03221. PAW acknowledges research funding from the South African National Research Foundation. RWW was funded by the Science and Technology Facilities Council grant ST/P000541/1. V.A.R.M.R. acknowledges financial support from Radboud Excellence Initiative, the Fundação para a Ciência e a Tecnologia (FCT) in the form of an exploratory project of reference IF/00498/2015/CP1302/CT0001, FCT and the Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through national funds and when applicable co-funded EU funds under the project UIDB/EEA/50008/2020, and supported by Enabling Green E-science for the Square Kilometre Array Research Infrastructure (ENGAGE-SKA), POCI-01-0145-FEDER-022217, and PHOBOS, POCI-01-0145-FEDER-029932, funded by Programa Operacional Competitividade e Internacionalização (COMPETE 2020) and FCT, Portugal. ZKR acknowledges funding from the Netherlands Research School for Astronomy (NOVA). ZN acknowledges support from the ESA PRODEX contract nr. 4000129910., With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709.
Published: 2021
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7. The Galactic Anticentre

Author: Vincenzo Ripepi, A. de Torres, Annie C. Robin, Mariateresa Crosta, C. Diener, L. Noval, Daniel Michalik, P. J. Richards, L. Karbevska, K. Kruszyńska, E. Fraile, André Moitinho, Michał Pawlak, P. Panuzzo, M. Riello, Benoit Carry, A. Yoldas, Harry Enke, N. Tonello, P. Gavras, M. Vaillant, Rosanna Sordo, E. del Pozo, Lorenzo Rimoldini, M. Bernet, G. Orrù, W. van Reeven, J. M. Martín-Fleitas, S. Diakite, P. Burgess, P. Osborne, Derek W. Morris, M. I. Carnerero, Amina Helmi, Mike Smith, Iain A. Steele, Alessandro Sozzetti, M. Kontizas, A. Sagristà Sellés, Roberto Molinaro, B. Holl, D. Baines, D. Molina, J. Fernández-Hernández, S. Marinoni, Michele Bellazzini, Maria Süveges, Teresa Antoja, D. Barbato, Uwe Lammers, Isabella Pagano, Davide Massari, G. Plum, P. Ramos, G. Jevardat de Fombelle, M. Biermann, C. Crowley, Mathias Schultheis, D. W. Evans, P. A. Palicio, Paolo Montegriffo, Ramachrisna Teixeira, R. Blomme, Elmé Breedt, T. A. Lister, F. A. Jansen, Ruth Carballo, Marcella Marconi, A. Abreu Aramburu, J. M. Carrasco, F. Royer, S. Accart, A. Burlacu, S. Regibo, Andrej Prsa, M. Sarasso, Nicolas Rambaux, A. F. Mulone, Ana Ulla, Eric Gosset, Alessandra Mastrobuono-Battisti, George M. Seabroke, H. E. Delgado, Federico Marocco, C. Nicolas, T. Lebzelter, Nami Mowlavi, C. Barache, Nicoletta Sanna, G. Gracia-Abril, R. Santoveña, R. Haigron, N. Unger, Silvio Leccia, A. Jean-Antoine Piccolo, A. F. Lanza, Alberto Vecchiato, Thomas Wevers, F. Figueras, G. Busso, C. Fabre, P. Di Matteo, F. Riclet, F. Solitro, Eric Slezak, N. Samaras, João Alves, Emese Plachy, Timo Prusti, F. van Leeuwen, J. Osinde, O. Marchal, M. Ajaj, C. Ducourant, Tatiana Muraveva, Shay Zucker, H. Steidelmüller, Alberto Riva, D. Semeux, N. Cheek, Laurent Galluccio, Martin A. Barstow, Alex Bombrun, S. Liao, M. van Leeuwen, R. E. de Souza, P. de Laverny, T. Roegiers, Paul J. McMillan, G. Holland, Alexey Mints, G. Giuffrida, L. M. Sarro, Juan Zorec, G. Sadowski, P. Yvard, Carme Jordi, J. L. Halbwachs, Laurent Chemin, Ludovic Delchambre, M. Garcia-Reinaldos, Ugo Becciani, Diego Bossini, Ángel Gómez, Sergi Blanco-Cuaresma, Rossella Cancelliere, C. Fabricius, J. De Ridder, L. Eyer, L. Pulone, Simon Hodgkin, Ennio Poretti, F. De Angeli, M. Haywood, E. Anglada Varela, Antonella Vallenari, F. X. Pineau, D. Garabato, A. Guerrier, H. E. P. Lindstrøm, Thomas Hilger, I. Bellas-Velidis, Frédéric Arenou, Paolo Giacobbe, Ilaria Musella, Tristan Cantat-Gaudin, L. Palaversa, Pedro García-Lario, David Hobbs, C. Turon, E. Balbinot, P. de Teodoro, Sébastien Lambert, D. Katz, Angela Bragaglia, Anthony G. A. Brown, Paolo Tanga, P. Castro Sampol, J. C. Segovia, Alejandra Recio-Blanco, Yves Fremat, Jon Marchant, Jose M Hernandez, S. Ragaini, Sofia Randich, P. Re Fiorentin, J. F. Le Campion, Gisella Clementini, M. Segol, P. David, R. Drimmel, F. Crifo, J. Guiraud, M. David, R. L. Smart, M. Fabrizio, I. Gonzalez-Santamaria, D. Eappachen, M. G. Lattanzi, Miguel García-Torres, Andreas Korn, S. Voutsinas, László Molnár, Simchon Faigler, A. Mora, Nicholas Rowell, Antti Penttilä, R. Geyer, Sanjeev Khanna, Aldo Dell'Oro, H. E. Huckle, C. Dolding, N. Leclerc, Monica Rainer, R. Mor, J. Bakker, Maroussia Roelens, Douglas J. Marshall, A. G. Butkevich, Nigel Hambly, A. Masip, Laia Casamiquela, R. Messineo, Martin Altmann, A. M. Piersimoni, Alessandro Spagna, Gerry Gilmore, Stefano Bertone, Patrick Charlot, O. Vanel, Daniel Hestroffer, Marco Castellani, Sebastian L. Hidalgo, W. Roux, Łukasz Wyrzykowski, Krzysztof A. Rybicki, M. M. S. Marcos Santos, Raphael Guerra, Alberto Cellino, E. Poggio, Gérard Jasniewicz, J. J. González-Vidal, S. Cowell, Peter G. Jonker, C. M. Raiteri, S. Bartolomé, J. Álvarez Cid-Fuentes, Elisabetta Caffau, J. J. Aguado, N. R. Millar, Ulrike Heiter, Federica Spoto, Felix Franke, A. Baudesson-Stella, M. Barros, Tsevi Mazeh, A. Panahi, E. Brugaletta, R. Buzzi, Elena Pancino, G. Altavilla, E. Racero, Enrique Solano, Mikael Granvik, Minia Manteiga, C. Robin, Tomaz Zwitter, Deborah Busonero, Alberto Krone-Martins, Marc Audard, Kevin Benson, Christos Siopis, L. Balaguer-Núñez, C. A. L. Bailer-Jones, E. Poujoulet, O. L. Creevey, E. Szegedi-Elek, C. Fouron, Michael Davidson, E. Licata, Despina Hatzidimitriou, Mark Cropper, Z. Kostrzewa-Rutkowska, S. Managau, A. Dapergolas, Sergio Messina, Laszlo Szabados, H. I. Siddiqui, W. Löffler, Mario Gai, J.-B. Delisle, Leanne P. Guy, S. G. Baker, W. J. Cooper, Alfred Castro-Ginard, Conny Aerts, A. Lorca, Xavier Luri, Damien Ségransan, Grigori Fedorets, A. Garofalo, J. Juaristi Campillo, F. De Luise, F. Pailler, F. Taris, L. Bramante, Thierry Morel, T. Cornez, L. Martin Polo, M. Ramos-Lerate, Jordi Portell, E. Salguero, Sergei A. Klioner, K. Janßen, Ulrich Bastian, Stefan Jordan, P. Esquej, A. C. Lanzafame, Beatrice Bucciarelli, C. Panem, Y. Lebreton, Carlos Dafonte, S. Girona, D. Munoz, Dimitri Pourbaix, William Thuillot, J. H. J. de Bruijne, N. Brouillet, L. Chaoul, F. Torra, Alex Lobel, J.-L. Bassilana, Francesca Fragkoudi, M. Romero-Gómez, C. A. Stephenson, T. Pauwels, Eva Sciacca, Alessandro Bressan, Morgan Fouesneau, E. Livanou, E. Gerlach, X. Peñalosa Esteller, Roberto Morbidelli, L. Rohrbasser, Johannes Sahlmann, Elisa Distefano, P. Sartoretti, Karri Muinonen, Zoltan Balog, Y. Viala, J. Torra, H. Zhao, L. Siltala, G. Tauran, D. Souami, P. Madrero Pardo, David Teyssier, Jesus Salgado, J. Souchay, C. P. Murphy, Maria-Rosa L. Cioni, N. A. Walton, S. Bouquillon, Andrea Chiavassa, Agnes Fienga, Giovanni Comoretto, F. Julbe, A. Hutton, Yassine Damerdji, Richard I. Anderson, Pierre Fernique, Céline Reylé, M. Hauser, E. Utrilla, Pierre Kervella, C. Zurbach, Robert G. Mann, Ummi Abbas, Hector Canovas, D. L. Harrison, Y. Lasne, Mark Taylor, Y. Le Fustec, E. F. del Peloso, N. Bauchet, E. van Dillen, Jan Rybizki, N. Hładczuk, T. Boch, J. González-Núñez, Carine Babusiaux, C. Pagani, Krzysztof Nienartowicz, Eduard Masana, G. Kordopatis, N. Robichon, Luciana Bianchi, R. Gutiérrez-Sánchez, Arnaud Siebert, A. Kochoska, T. Carlucci, Jérôme Berthier, J. Castañeda, D. Vicente, R. De March, A. Garcia-Gutierrez, M. Weiler, F. Thévenin, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Guy Rixon, Francois Mignard, P. M. Marrese, M. A. Álvarez, Caroline Soubiran, Rene Andrae, C. Ordénovic, A. Delgado, V. Sanchez Gimenez, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Universidad de Barcelona, Xunta de Galicia, European Commission, Centros de Excelencia Severo Ochoa, BARCELONA SUPERCOMPUTING CENTER (BSC), SEV2015-0493, Krone Martins, A. [0000-0002-2308-6623], McMillan, P. [0000-0002-8861-2620], Carrasco Martínez, J. P. [0000-0002-3029-5853], Sozzetti, A. [0000-0002-7504-365X], Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MINECO/ICTI2013-2016/MDM-2014-0369, Centrode Excelencia Científica Instituto de Ciencias del Cosmos Universidad de Barcelona, MINECO/ICTI2013-2016/SEV2015-0493, Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), National Natural Science Foundation of China (NSFC), Estonian Ministry of Education and Research, Centre National D'Etudes Spatiales (CNES), Agence Nationale de la Recherche (ANR), Centre National de la Recherche Scientifique (CNRS), European Commission (EC), European Research Council (ERC), Institut des Sciences de l'Univers (INSU), Institut National Polytechnique (INP), Institut National de Physique nucleaire et de Physique des Particules (IN2P3), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Hungarian Academy of Sciences, Hungarian National Research, Development, and Innovation Office (NKFIH), Science Foundation Ireland (SFI), Israel Science Foundation (ISF), Agenzia Spaziale Italiana (ASI), Italian Istituto Nazionale di Astrofisica (INAF), Netherlands Organisation for Scientific Research (NWO), Polish National Science Centre, Ministry of Science and Higher Education (MNiSW), Fundacao para a Ciencia e a Tecnologia (FCT), Slovenian Research Agency, Agencia Estatal de Investigación (AEI), Generalitat de Catalunya, United Kingdom Science and Technology Facilities Council (STFC), United Kingdom Space Agency (UKSA), Gaia Collaboration, Universidad de Cantabria, Astronomy, Kapteyn Astronomical Institute, Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), M2A 2021, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), 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), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Planetary-system research, Department of Physics, Particle Physics and Astrophysics, Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: trigonometric parallaxes, SOLAR NEIGHBORHOOD, Astronomy, SAGITTARIUS DWARF GALAXY, Astrophysics, 01 natural sciences, sagittarius dwarf galaxy, 010303 astronomy & astrophysics, Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], solar neighborhood, Astrophysics::Instrumentation and Methods for Astrophysics, Astrometry, Gelexy: kinematics and dynamics, Kinematics and Dynamics, Open clusters and asssociations: individual: Berkeley 29, sky survey, Disk, Physical Sciences, kinematics and dynamics [Gelexy], old open clusters, MILKY-WAY, Astrophysics::Earth and Planetary Astrophysics, open clusters and associations: individual: Berkeley 29, Galaxy: kinematics and dynamics, disk [Galaxy], individual: Berkeley 29 [open clusters and associations], Astrometria, Berkeley 29, EXPLORING HALO SUBSTRUCTURE, LOCAL KINEMATICS, Milky Way, FOS: Physical sciences, Open Clusters and Associations, Individual, exploring halo substructure, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Computer Science::Digital Libraries, stellar structure, Galaxy: disk, Open clusters and associations: individual: Saurer 1, Galactic halo, Halo, Settore FIS/05 - Astronomia e Astrofisica, individual: Berkeley 29 [Open clusters and asssociations], 0103 physical sciences, distances [stars], halo [Galaxy], Disc, Stars: distances, milky-way, Saurer 1, Astrophysics::Galaxy Astrophysics, canis-major, Science & Technology, 010308 nuclear & particles physics, TRIGONOMETRIC PARALLAXES, Galaxy: halo, stars: distances, open clusters and associations: individual: Saurer 1, Astrophysics - Astrophysics of Galaxies, Astronomy and Astrophysics, Galactic plane, kinematics and dynamics [Galaxy], 115 Astronomy, Space science, CANIS-MAJOR, Stars, Galaxy, Physics::History of Physics, Estels, individual: Saurer 1 [open clusters and associations], Distances, local kinematics, OLD OPEN CLUSTERS, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), SKY SURVEY, Open cluster, STELLAR STRUCTURE
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.
Published: 2021
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8. Dipper-like variability of the Gaia alerted young star V555 Ori

Author: László Mészáros, O. Hanyecz, Gabriella Zsidi, András Pál, Ádám Sódor, Elza Szegedi-Elek, Laszlo Szabados, D. Tarczay-Nehéz, Ágnes Kóspál, Simon Hodgkin, Péter Ábrahám, A. Ordasi, R. Szakats, Gábor Marton, A. Bódi, Csaba Kiss, R. Konyves-Toth, Mária Kun, A. Moór, L. Kriskovics, Zsófia Nagy, B. Ignácz, B. Cseh, Jerome Bouvier, Krisztián Vida, Zsófia Marianna Szabó, Anikó Farkas-Takács, Paula Sarkis, and Krisztián Sárneczky
Subjects: Physics, Brightness, Accretion (meteorology), 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Extinction (astronomy), FOS: Physical sciences, Flux, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Light curve, 01 natural sciences, T Tauri star, Wavelength, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Variation (astronomy), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: V555 Ori is a T Tauri star, whose 1.5 mag brightening was published as a Gaia science alert in 2017. We carried out optical and near-infrared photometric, and optical spectroscopic observations to understand the light variations. The light curves show that V555 Ori was faint before 2017, entered a high state for about a year, and returned to the faint state by mid-2018. In addition to the long-term flux evolution, quasi-periodic brightness oscillations were also evident, with a period of about 5 days. At optical wavelengths both the long-term and short-term variations exhibited colourless changes, while in the near-infrared they were consistent with changing extinction. We explain the brightness variations as the consequence of changing extinction. The object has a low accretion rate whose variation in itself would not be enough to reproduce the optical flux changes. This behaviour makes V555 Ori similar to the pre-main sequence star AA Tau, where the light changes are interpreted as periodic eclipses of the star by a rotating inner disc warp. The brightness maximum of V555 Ori was a moderately obscured ($A_V$=2.3 mag) state, while the extinction in the low state was $A_V$=6.4 mag. We found that while the Gaia alert hinted at an accretion burst, V555 Ori is a standard dipper, similar to the prototype AA Tau. However, unlike in AA Tau, the periodic behaviour was also detectable in the faint phase, implying that the inner disc warp remained stable in both the high and low states of the system., Accepted to MNRAS
Published: 2021
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9. Gaia early data release 3: summary of the contents and survey properties (Corrigendum)

Author: Mathias Schultheis, Marcella Marconi, N. Robichon, Luciana Bianchi, F. Crifo, J. Guiraud, D. Eappachen, R. Gutiérrez-Sánchez, Sanjeev Khanna, A. M. Piersimoni, Raphael Guerra, J. J. González-Vidal, J. J. Aguado, N. R. Millar, A. Baudesson-Stella, Tristan Cantat-Gaudin, Alejandra Recio-Blanco, Ummi Abbas, Francesca Figueras, R. Blomme, Elmé Breedt, G. Busso, A. Jean-Antoine Piccolo, Gerry Gilmore, A. Panahi, S. Messina, C. Babusiaux, Łukasz Wyrzykowski, Mark Taylor, Alex Bombrun, M. Barros, M. Riello, M. Ajaj, C. Ducourant, Tatiana Muraveva, Alberto Cellino, E. Poggio, Y. Le Fustec, C. P. Murphy, Maria-Rosa L. Cioni, Hector Canovas, D. L. Harrison, Y. Lasne, Elena Pancino, N. Bauchet, G. Orrù, Sergi Blanco-Cuaresma, Simon Hodgkin, Ennio Poretti, A. F. Lanza, Alberto Vecchiato, Thomas Wevers, Andrea Chiavassa, E. Szegedi-Elek, A. G. A. Brown, Laszlo Szabados, A. Masip, Laia Casamiquela, R. Messineo, C. Crowley, Alessandra Mastrobuono-Battisti, E. Poujoulet, Zoltan Balog, L. Eyer, A. Guerrier, H. E. P. Lindstrøm, Ilaria Musella, Laurent Galluccio, Martin A. Barstow, Aldo Dell'Oro, Mark Cropper, Z. Kostrzewa-Rutkowska, Angela Bragaglia, Arnaud Siebert, Damien Ségransan, A. Kochoska, J. L. Halbwachs, E. F. del Peloso, N. Hładczuk, F. Pailler, Stefan Jordan, Stefano Bertone, L. Pulone, Frédéric Arenou, Patrick Charlot, David Hobbs, P. Castro Sampol, Yves Fremat, Sofia Randich, Marc Audard, Despina Hatzidimitriou, A. Dapergolas, L. Palaversa, W. van Reeven, M. Hauser, E. Utrilla, Georges Kordopatis, Sergei A. Klioner, Alex Lobel, J.-L. Bassilana, G. Tauran, T. Prusti, H. Steidelmüller, Alberto Riva, Diego Bossini, Maria Süveges, Isabella Pagano, J. H. J. de Bruijne, Elisabetta Caffau, Federica Spoto, Felix Franke, T. Boch, M. I. Carnerero, T. Carlucci, Grigori Fedorets, J. Castañeda, W. Löffler, Enrique Solano, Paolo Montegriffo, A. Abreu Aramburu, T. Lebzelter, Nami Mowlavi, C. Barache, C. A. Stephenson, A. Lorca, L. Bramante, Amina Helmi, J.-B. Delisle, B. Holl, D. Molina, J. Fernández-Hernández, G. Jevardat de Fombelle, F. van Leeuwen, C. Robin, D. Katz, E. Gerlach, Elisa Distefano, Michele Bellazzini, P. de Laverny, G. Sadowski, Tomaz Zwitter, A. Burlacu, Teresa Antoja, Rossella Cancelliere, F. Torra, C. Pagani, Annie C. Robin, Johannes Sahlmann, Karri Muinonen, Eva Sciacca, D. Vicente, Krzysztof Nienartowicz, A. F. Mulone, Shay Zucker, Nicholas Rowell, H. E. Delgado, Dimitri Pourbaix, G. Giuffrida, H. E. Huckle, Federico Marocco, L. Noval, Daniel Michalik, P. J. Richards, Y. Viala, E. van Dillen, L. Karbevska, H. Zhao, L. Siltala, Nicoletta Sanna, K. Kruszyńska, E. Fraile, R. De March, Y. Lebreton, C. M. Raiteri, D. W. Evans, Ana Ulla, Francesca Fragkoudi, Jan Rybizki, E. Brugaletta, L. Rohrbasser, Andreas Korn, S. G. Baker, A. Garcia-Gutierrez, L. M. Sarro, R. Buzzi, T. Pauwels, Jérôme Berthier, L. Chaoul, W. J. Cooper, Eduard Masana, M. van Leeuwen, D. Garabato, P. Panuzzo, Maroussia Roelens, Benoit Carry, Deborah Busonero, Michael Davidson, J. González-Núñez, Thomas Hilger, E. Licata, M. Weiler, Mikael Granvik, Alessandro Bressan, Morgan Fouesneau, Miguel García-Torres, W. Roux, Pedro García-Lario, Iain A. Steele, P. Ramos, Alessandro Sozzetti, Roberto Molinaro, O. L. Creevey, D. Barbato, Lorenzo Rimoldini, Uwe Lammers, Alexey Mints, P. Sartoretti, E. Livanou, D. Souami, P. Madrero Pardo, David Teyssier, M. Bernet, Yassine Damerdji, X. Peñalosa Esteller, C. Fabre, F. Thévenin, Gérard Jasniewicz, Roberto Morbidelli, Jesus Salgado, Juan Zorec, Ángel Gómez, Douglas J. Marshall, A. G. Butkevich, M. Biermann, E. Racero, J. Torra, R. Gomel, O. Vanel, Daniel Hestroffer, Sebastian L. Hidalgo, P. A. Palicio, F. De Angeli, Richard L. Smart, J. M. Martín-Fleitas, Derek W. Morris, F. Royer, S. Diakite, S. Accart, C. Dolding, P. Burgess, Richard I. Anderson, A. Garofalo, I. Bellas-Velidis, George M. Seabroke, P. Osborne, Claus Fabricius, Jon Marchant, Ramachrisna Teixeira, João Alves, G. Gracia-Abril, R. Santoveña, R. Haigron, N. Unger, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Paolo Giacobbe, Emese Plachy, M. Fabrizio, I. Gonzalez-Santamaria, F. Taris, Kevin Benson, Christos Siopis, M. M. S. Marcos Santos, S. Cowell, Jose M Hernandez, S. Ragaini, Jordi Portell, Linda K. Molnar, R. Drimmel, Pierre Kervella, C. Zurbach, S. Bartolomé, J. Álvarez Cid-Fuentes, E. Salguero, Ulrich Bastian, Robert G. Mann, Marco Castellani, J. Osinde, E. Balbinot, Caroline Soubiran, Rene Andrae, J. Souchay, M. G. Lattanzi, S. Voutsinas, Agnes Fienga, Giovanni Comoretto, P. Esquej, A. C. Lanzafame, Beatrice Bucciarelli, C. Panem, Carlos Dafonte, Alfred Castro-Ginard, J. C. Segovia, Monica Rainer, F. Julbe, A. Hutton, Peter G. Jonker, William Thuillot, A. de Torres, F. De Luise, Pierre Fernique, Céline Reylé, M. Kontizas, G. Plum, Martin Altmann, L. Martin Polo, M. Ramos-Lerate, P. de Teodoro, Sébastien Lambert, G. Altavilla, André Moitinho, D. Munoz, N. Brouillet, Alessandro Spagna, C. Ordénovic, Gisella Clementini, C. Nicolas, Michał Pawlak, Silvio Leccia, A. Delgado, M. Romero-Gómez, N. Cheek, A. Yoldas, Harry Enke, Rosanna Sordo, V. Sanchez Gimenez, Mike Smith, P. David, D. Baines, Paolo Tanga, Guy Rixon, Alberto Krone-Martins, S. Managau, N. A. Walton, S. Bouquillon, C. Fouron, Francois Mignard, Xavier Luri, J. Juaristi Campillo, S. Girona, Thierry Morel, T. Cornez, P. M. Marrese, M. A. Álvarez, S. Liao, Andrej Prsa, M. Sarasso, Nicolas Rambaux, Paul J. McMillan, Ludovic Delchambre, M. Garcia-Reinaldos, M. Haywood, E. Anglada Varela, Antonella Vallenari, S. Regibo, R. E. de Souza, Sahar Shahaf, J. De Ridder, M. Segol, Simchon Faigler, A. Mora, Ulrike Heiter, Carla Cacciari, Minia Manteiga, H. I. Siddiqui, Mario Gai, Leanne P. Guy, N. Leclerc, T. A. Lister, F. A. Jansen, Ruth Carballo, J. M. Carrasco, Bengt Edvardsson, P. Di Matteo, K. Janßen, F. Riclet, F. Solitro, O. Marchal, G. Holland, F. X. Pineau, C. Turon, P. Re Fiorentin, Tsevi Mazeh, Mariateresa Crosta, C. Diener, J. F. Le Campion, Vincenzo Ripepi, M. David, R. Mor, N. Tonello, E. del Pozo, J. Bakker, Davide Massari, A. Sagristà Sellés, Marco Delbo, Eric Slezak, P. Gavras, N. Samaras, S. Marinoni, M. Vaillant, J. M. Petit, P. Yvard, Carme Jordi, Ugo Becciani, Antti Penttilä, R. Geyer, Nigel Hambly, Krzysztof A. Rybicki, L. Balaguer-Núñez, C. A. L. Bailer-Jones, Conny Aerts, Eric Gosset, D. Semeux, T. Roegiers, and Laurent Chemin
Subjects: Physics, Addenda, 010504 meteorology & atmospheric sciences, Errata, Parallaxes, Astronomy, Astronomy and Astrophysics, Astrophysics, Astrometry, Photometric, 01 natural sciences, Techniques, catalogs, astrometry, parallaxes, proper motions, techniques: photometric, errata, addenda, Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, 0103 physical sciences, Proper motions, Catalogs, 010303 astronomy & astrophysics, Data release, 0105 earth and related environmental sciences
Abstract: We present the early installment of the third Gaia data release, Gaia EDR3, consisting of astrometry and photometry for 1.8 billion sources brighter than magnitude 21, complemented with the list of radial velocities from Gaia DR2. Gaia EDR3 contains celestial positions and the apparent brightness in G for approximately 1.8 billion sources. For 1.5 billion of those sources, parallaxes, proper motions, and the (G_BP-G_RP) colour are also available. The passbands for G, G_BP, and G_RP are provided as part of the release. For ease of use, the 7 million radial velocities from Gaia DR2 are included in this release, after the removal of a small number of spurious values. New radial velocities will appear as part of Gaia DR3. Finally, Gaia EDR3 represents an updated materialisation of the celestial reference frame (CRF) in the optical, the Gaia-CRF3, which is based solely on extragalactic sources. The creation of the source list for Gaia EDR3 includes enhancements that make it more robust with respect to high proper motion stars, and the disturbing effects of spurious and partially resolved sources. The source list is largely the same as that for Gaia DR2, but it does feature new sources and there are some notable changes. The source list will not change for Gaia DR3. Gaia EDR3 represents a significant advance over Gaia DR2, with parallax precisions increased by 30 percent, proper motion precisions increased by a factor of 2, and the systematic errors in the astrometry suppressed by 30--40 percent for the parallaxes and by a factor ~2.5 for the proper motions. The photometry also features increased precision, but above all much better homogeneity across colour, magnitude, and celestial position. A single passband for G, G_BP, and G_RP is valid over the entire magnitude and colour range, with no systematics above the 1 percent level.
Published: 2021

10. Review of synergic meteor observations: linking the results from cameras, ionosondes, infrasound and seismic detectors

Author: Ákos Kereszturi, Cs. Czanik, Barta, P. Monus, A. Igaz, D Rezes, Bernadett Pál, I. Bondar, and Laszlo Szabados
Subjects: Shock wave, Physics, Meteor (satellite), Daytime, 010504 meteorology & atmospheric sciences, Meteoroid, Infrasound, Detector, FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Atmosphere, Space and Planetary Science, 0103 physical sciences, Ionosphere, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Remote sensing
Abstract: Joint evaluation of different meteor observation types support the better understanding of both the meteor phenomenon and the terrestrial atmosphere. Two types of examples are presented in this work, linking ionospheric effects to specific meteors, where almost one third of the meteors emerged at high altitudes were simultaneously recorded with an optical camera. Very few such observations have been realized yet. With a daytime fireball, the recorded infrasound effect and the atmospheric blast produced shock wave related small earthquakes were identified by a network of ground stations. The overview of these observational types highlights specific topics where substantial improvements and discoveries are expected in the near future., Comment: Accepted for publication in MNRAS
Published: 2021
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11. TESS observations of Cepheid stars: first light results

Author: Vincenzo Ripepi, M. J. Kalaee, Nicolas Nardetto, James M. Nemec, Laszlo Szabados, László Molnár, Dogus Ozuyar, Emese Plachy, Marek Skarka, M. Ebadi, Roland Vanderspek, Bogumił Pilecki, Jørgen Christensen-Dalsgaard, J. Pascual-Granado, M. I. Jurkovic, George R. Ricker, Kosmas Gazeas, P. Mikołajczyk, Á. Sódor, Pál Szabó, Radosław Smolec, Róbert Szabó, Anupam Bhardwaj, Earl P. Bellinger, Amir Hasanzadeh, Henryka Netzel, Franz-Josef Hambsch, András Pál, A. Bódi, Jon M. Jenkins, József Benkő, Katrien Kolenberg, Richard I. Anderson, Pierre Kervella, Chow-Choong Ngeow, Hans Kjeldsen, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Côte d'Azur (UCA), National Research, Development and Innovation Office (Hungary), Hungarian Academy of Sciences, Ministry of Science and Technology (Taiwan), European Commission, European Research Council, Danish National Research Foundation, National Science Centre (Poland), Ministry of Education, Science and Technological Development (Serbia), Ministerio de Ciencia, Innovación y Universidades (España), Agence Nationale de la Recherche (France), European Cooperation in Science and Technology, and Physics
Subjects: Cepheid variable stars, Field (physics), Cepheid variable, Overtone, Stellar photometry, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, Stellar pulsations, 7. Clean energy, 01 natural sciences, 0103 physical sciences, Modulation (music), Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, Science & Technology, 010308 nuclear & particles physics, Mode (statistics), Astronomy and Astrophysics, First light, Light curve, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Physical Sciences, Astrophysics::Earth and Planetary Astrophysics
Abstract: Full list of authors: Plachy, E.; Pál, A.; Bódi, A.; Szabó, P.; Molnár, L.; Szabados, L.; Benkő, J. M.; Anderson, R. I.; Bellinger, E. P.; Bhardwaj, A.; Ebadi, M.; Gazeas, K.; Hambsch, F. -J.; Hasanzadeh, A.; Jurkovic, M. I.; Kalaee, M. J.; Kervella, P.; Kolenberg, K.; Mikołajczyk, P.; Nardetto, N. Nemec, J. M.; Netzel, H.; Ngeow, C. -C.; Ozuyar, D.; Pascual-Granado, J.; Pilecki, B.; Ripepi, V.; Skarka, M.; Smolec, R.; Sódor, Á.; Szabó, R.; Christensen-Dalsgaard, J.; Jenkins, J. M.; Kjeldsen, H.; Ricker, G. R.; Vanderspek, R., We present the first analysis of Cepheid stars observed by the TESS space mission in Sectors 1–5. Our sample consists of 25 pulsators: ten fundamental mode, three overtone and two double-mode classical Cepheids, plus three type II and seven anomalous Cepheids. The targets were chosen from fields with different stellar densities, both from the Galactic field and from the Magellanic System. Three targets have 2 minutes cadence light curves available by the TESS Science Processing Operations Center: for the rest, we prepared custom light curves from the full-frame images with our own differential photometric FITSH pipeline. Our main goal was to explore the potential and the limitations of TESS concerning the various subtypes of Cepheids. We detected many low-amplitude features: weak modulation, period jitter, and timing variations due to light-time effect. We also report signs of nonradial modes and the first discovery of such a mode in an anomalous Cepheid, the overtone star XZ Cet, which we then confirmed with ground-based multicolor photometric measurements. We prepared a custom photometric solution to minimize saturation effects in the bright fundamental-mode classical Cepheid, β Dor with the lightkurve software, and we revealed strong evidence of cycle-to-cycle variations in the star. In several cases, however, fluctuations in the pulsation could not be distinguished from instrumental effects, such as contamination from nearby sources, which also varies between sectors. Finally, we discuss how precise light-curve shapes will be crucial not only for classification purposes but also to determine physical properties of these stars. © 2021. The American Astronomical Society. All rights reserved., The research leading to these results has been supported by the Hungarian National Research, Development and Innovation Office (NKFIH) grants KH_18 130405, K-125015, GINOP 2.3.2-15-2016-00033, and NN-129075, and the Lendulet LP2014-17 and LP2018-7/2020 grants of the Hungarian Academy of Sciences (HAS). The work reported on in this publication has been supported by the MW-Gaia COST Action (CA18104). Partial funding of the computational infrastructure and database servers were received from the grant KEP-7/2018 of the HAS. E.P. was supported by the Janos Bolyai Research Scholarship of the HAS. L.M. was supported by the Premium Postdoctoral Research Program of the HAS. C.C.N. thanks the funding from Ministry of Science and Technology (Taiwan) under the contract 107-2119-M-008014-MY2. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (grant agreement No. DNRF106). R.Sm. was supported by the National Science Center, Poland, Sonata BIS project 2018/30/E/ST9/00598. M.I.J. was supported by the Ministry of Education, Science and Technological Development (contract number 451-03-68/2020-14/200002) of Republic of Serbia. A.B. acknowledges a Gruber fellowship 2020 grant sponsored by the Gruber Foundation and the International Astronomical Union and is supported by the EACOA Fellowship Program under the umbrella of the East Asia Core Observatories Association, which consists of the Academia Sinica Institute of Astronomy and Astrophysics, the National Astronomical Observatory of Japan, the Korea Astronomy and Space Science Institute, and the National Astronomical Observatories of the Chinese Academy of Sciences. J.P.G. acknowledges financial support from the State Agency for Research of the Spanish MCIU through the "Center of Excellence Severo Ochoa" award to the Instituto de Astrofisica de Andalucia (SEV-2017-0709) and from Spanish public funds for research under project ESP2017-87676-C5-5-R. P.M. acknowledges support from the NCN grant No. 2016/21/B/ST9/01126. M.S. acknowledges the financial support of the Operational Program Research, Development and Education-Project Postdoc@MUNI(No.CZ.02.2.69/0.0/0.0/16_027/0008360) and the MSMT Inter Transfer program LTT20015. P.K. and N.N. acknowledge the support of the French Agence Nationale de la Recherche (ANR), under grant ANR-15-CE31-0012-01 (project UnlockCepheids). The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement No. 695099). This work has made use of data from the European Space Agency (ESA) mission Gaia (http://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, http://www.cosmos.esa.int/web/gaia/dpac/consortium).Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by NASAs Science Mission directorate. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products.
Published: 2020
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12. Gaia 18dvy: A New FUor in the Cygnus OB3 Association

Author: L. Chen, Etienne Bachelet, L. Mészáros, V. Čepas, H. Netzel, Umut Burgaz, B. Seli, K. Vida, Timothy Butterley, R. Bischoff, A. Simon, Péter Ábrahám, András Pál, Z. Kaczmarek, L. Tomasella, Ágnes Kóspál, Yiannis Tsapras, Csaba Kiss, K. Kruszyńska, A. Ordasi, Goran Damljanović, Łukasz Wyrzykowski, M. Maskoliūnas, K. Šiškauskaitė, P. Mikołajczyk, O. Ziółkowska, Elmé Breedt, A. Moór, Rachel Street, Mate Krezinger, Markus Mugrauer, W. Stenglein, Susanne M. Hoffmann, P. Zielinski, József Varga, Ádám Sódor, R. Szakats, E. Varga-Verebélyi, Gábor Marton, M. Hundertmark, Krisztián Sárneczky, L. K. Hardy, Mariusz Gromadzki, Rimvydas Janulis, R. Konyves-Toth, J. M. Carrasco, Felix Hildebrandt, M. Zielinski, J. Zdanavičius, M. Kun, Krzysztof A. Rybicki, E. Szegedi-Elek, S. P. Littlefair, Kirill Sokolovsky, I. Gezer, Attila Bódi, A. Gurgul, E. Pakštienė, Cs. Kalup, N. Ihanec, V. Godunova, C. Andreas, Laszlo Szabados, European Commission, Hungarian Academy of Sciences, National Research, Development and Innovation Office (Hungary), Research Council of Lithuania, Ministry of Education, Science and Technological Development (Serbia), Ministerio de Economía y Competitividad (España), Michigan State University, and Ege Üniversitesi
Subjects: Physics, Protoplanetary disks, Accretion, 010308 nuclear & particles physics, Star formation, media_common.quotation_subject, Kiss, FOS: Physical sciences, Eruptive variable stars, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Accretion (astrophysics), Machine-readable table, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), media_common
Abstract: Full author list: E. Szegedi-Elek, P. Ábrahám, Ł. Wyrzykowski, M. Kun, Á. Kóspál, L. Chen, G. Marton, A. Moór, C. Kiss, A. Pál, L. Szabados, J. Varga, E. Varga-Verebélyi, C. Andreas, E. Bachelet, R. Bischoff, A. Bódi, E. Breedt, U. Burgaz, T. Butterley, J. M. Carrasco, V. Čepas, G. Damljanovic, I. Gezer, V. Godunova, M. Gromadzki, A. Gurgul, L. Hardy, F. Hildebrandt, S. Hoffmann, M. Hundertmark, N. Ihanec, R. Janulis, Cs. Kalup, Z. Kaczmarek, R. Könyves-Tóth, M. Krezinger, K. Kruszyńska, S. Littlefair, M. Maskoliūnas, L. Mészáros, P. Mikołajczyk, M. Mugrauer, H. Netzel, A. Ordasi, E. Pakštienė, K. A. Rybicki, K. Sárneczky, B. Seli, A. Simon, K. Šiškauskaitė, Á. Sódor, K. V. Sokolovsky2, W. Stenglein, R. Street, R. Szakáts, L. Tomasella, Y. Tsapras, K. Vida, J. Zdanavičius, M. Zieliński, P. Zieliński, and O. Ziółkowska, We present optical-infrared photometric and spectroscopic observations of Gaia 18dvy, located in the Cygnus OB3 association at a distance of 1.88 kpc. Gaia 18dvy was noted by the Gaia alerts system when its light curve exhibited a ⪆4 mag rise in 2018-2019. The brightening was also observable at mid-infared wavelengths. The infrared colors of Gaia 18dvy became bluer as the outburst progressed. Its optical and near-infrared spectroscopic characteristics in the outburst phase are consistent with those of bona fide FU Orionis-type young eruptive stars. The progenitor of the outburst is probably a low-mass K-type star with an optical extinction of ∼3 mag. A radiative transfer modeling of the circumstellar structure, based on the quiescent spectral energy distribution, indicates a disk with a mass of 4 10-3 M o˙. Our simple accretion disk modeling implies that the accretion rate had been exponentially increasing for more than 3 yr until mid-2019, when it reached a peak value of 6.9 10-6 M o˙ yr-1. In many respects, Gaia 18dvy is similar to the FU Ori-type object HBC 722., We thank the anonymous referee, whose questions and comments significantly improved the paper. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program under grant agreement No. 716155 (SACCRED), Lendület LP2018-7/2019 and KEP-7/2018 of the Hungarian Academy of Sciences, GINOP 2.3.2-15-2016-00003 and PD-128360 of the Hungarian National Research, Development and Innovation Office, Polish NCN DAINA grant 2017/27/ L/ST9/03221, European Commission’s Horizon 2020 OPTICON grant 730890, Polish MNiSW grant DIR/WK/2018/12, grant No. S-LL-19-2 of the Research Council of Lithuania, Project No. 176011 “Dynamics and kinematics of celestial bodies and systems” of the Ministry of Education, Science and Technological Development of the Republic of Serbia, DFG priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (WA 1047/11-1), the MINECO (Spanish Ministry of Economy) through grant RTI2018-095076-B-C21 (MINECO/FEDER, UE). The Joan Oró Telescope (TJO) of the Montsec Astronomical Observatory (OAdM) is owned by the Catalan Government and is operated by the Institute for Space Studies of Catalonia (IEEC). MG is supported by the Polish NCN MAESTRO grant 2014/14/ A/ST9/00121. We acknowledge ESA Gaia, DPAC, and the Photometric Science Alerts Team. We thank Christina Conner, Megan Davis, Alessandro Dellarovere, Hannah Gallamore, Mira Ghazali, Aaron Kruskie, Dylan Mankel, Jesse Leahy–McGregor, Brandon McIntyre, Barrett Ross, Courtney Wicklund, and Evan Zobel for observing Gaia 18dvy at the Michigan State University Observatory. Based on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias. Based on observations obtained with telescopes of the University Observatory Jena, which is operated by the Astrophysical Institute of the Friedrich-Schiller-University.
Published: 2020

13. Gaia Early Data Release 3: Acceleration of the solar system from Gaia astrometry

Author: Vincenzo Ripepi, P. Gavras, M. Vaillant, Mathias Schultheis, László Molnár, E. Poujoulet, Mark Cropper, C. Babusiaux, D. Molina, J. Fernández-Hernández, G. Jevardat de Fombelle, A. de Torres, Aldo Dell'Oro, J. Castañeda, Z. Kostrzewa-Rutkowska, A. Bombrun, André Moitinho, Marcella Marconi, Rossella Cancelliere, M. Hauser, M. Ajaj, C. M. Raiteri, L. Eyer, Michał Pawlak, H. I. Siddiqui, C. Ducourant, Tatiana Muraveva, Tsevi Mazeh, A. Panahi, Federico Marocco, Stefano Bertone, D. Vicente, Patrick Charlot, A. Guerrier, R. De March, Mario Gai, J. Souchay, H. E. P. Lindstrøm, Nicoletta Sanna, Agnes Fienga, Giovanni Comoretto, Jon Marchant, A. Lorca, E. Utrilla, A. Garcia-Gutierrez, Ilaria Musella, L. Balaguer-Núñez, Leanne P. Guy, N. Leclerc, E. Brugaletta, A. Yoldas, Harry Enke, Rosanna Sordo, Zoltan Balog, H. E. Huckle, L. Palaversa, Monica Rainer, T. A. Lister, F. A. Jansen, Ruth Carballo, Alessandro Spagna, J. M. Carrasco, Mikael Granvik, Derek W. Morris, F. Julbe, A. Hutton, J. Osinde, D. W. Evans, M. van Leeuwen, M. Weiler, F. Thévenin, F. Torra, Iain A. Steele, Lorenzo Rimoldini, Alessandro Sozzetti, Francesca Fragkoudi, K. Janßen, O. L. Creevey, J. González-Núñez, T. Pauwels, R. Buzzi, Miguel García-Torres, S. Liao, G. Tauran, Lennart Lindegren, C. Fouron, Pierre Fernique, Céline Reylé, P. Di Matteo, E. Szegedi-Elek, F. Pailler, Stefan Jordan, Roberto Molinaro, Elisabetta Caffau, Federica Spoto, Felix Franke, D. Barbato, Isabelle Lecoeur-Taïbi, Tristan Cantat-Gaudin, Alejandra Recio-Blanco, E. Livanou, W. Roux, X. Peñalosa Esteller, P. A. Palicio, J. H. J. de Bruijne, Sergi Blanco-Cuaresma, Deborah Busonero, F. Riclet, Conny Aerts, Georges Kordopatis, Guy Rixon, F. Solitro, Davide Massari, Mike Smith, D. Baines, Roberto Morbidelli, Gerry Gilmore, G. Plum, Alexey Mints, O. Marchal, Juan Zorec, Ángel Gómez, C. A. Stephenson, Michael Davidson, C. Fabricius, E. Licata, Sergio Messina, Laszlo Szabados, M. Biermann, A. Garofalo, G. Holland, F. De Angeli, Andreas Korn, E. Anglada Varela, Grigori Fedorets, S. Girona, E. Gerlach, Antonella Vallenari, M. Riello, Łukasz Wyrzykowski, Damien Ségransan, F. Taris, L. Bramante, Alberto Cellino, S. Regibo, Andrej Prsa, M. Sarasso, E. Poggio, W. Löffler, Paolo Giacobbe, Jordi Portell, Elisa Distefano, Eric Slezak, I. Bellas-Velidis, Nicolas Rambaux, E. Balbinot, J.-B. Delisle, Maroussia Roelens, E. Salguero, P. de Teodoro, E. van Dillen, Y. Lebreton, Francois Mignard, Sergei A. Klioner, Ulrich Bastian, N. Samaras, G. Orrù, R. E. de Souza, P. Esquej, Paul J. McMillan, A. C. Lanzafame, Sébastien Lambert, Beatrice Bucciarelli, Jose M Hernandez, M. Bernet, S. Ragaini, Gisella Clementini, A. F. Mulone, Ludovic Delchambre, C. Panem, Eric Gosset, P. David, M. Garcia-Reinaldos, Ana Ulla, F. Crifo, J. Guiraud, Mariateresa Crosta, L. Chaoul, C. Diener, Carlos Dafonte, Karri Muinonen, Alex Lobel, J.-L. Bassilana, Maria Süveges, Isabella Pagano, Dimitri Pourbaix, D. Eappachen, M. Haywood, R. Drimmel, Y. Viala, S. Voutsinas, D. Semeux, William Thuillot, N. A. Walton, Paolo Montegriffo, A. Abreu Aramburu, C. Fabre, H. Zhao, Alessandro Bressan, S. Bouquillon, Sanjeev Khanna, T. Lebzelter, N. Tonello, L. Siltala, M. G. Lattanzi, C. Crowley, P. Yvard, Carme Jordi, Elena Pancino, E. del Pozo, Jan Rybizki, Nami Mowlavi, C. Barache, Morgan Fouesneau, J. De Ridder, Ugo Becciani, Martin Altmann, F. van Leeuwen, P. M. Marrese, M. A. Álvarez, A. Jean-Antoine Piccolo, A. F. Lanza, Alberto Vecchiato, Thomas Wevers, Caroline Soubiran, C. P. Murphy, A. M. Piersimoni, Alessandra Mastrobuono-Battisti, Peter G. Jonker, A. Sagristà Sellés, T. Roegiers, S. Marinoni, Johannes Sahlmann, Rene Andrae, P. Sartoretti, G. Altavilla, Raphael Guerra, F. X. Pineau, M. Segol, T. Prusti, J. J. González-Vidal, J. J. Aguado, N. R. Millar, A. Baudesson-Stella, Andrea Chiavassa, Laurent Chemin, C. Turon, H. Steidelmüller, Douglas J. Marshall, A. G. Butkevich, Alberto Riva, P. de Laverny, Simchon Faigler, Laurent Galluccio, A. Mora, P. Re Fiorentin, C. Ordénovic, J. F. Le Campion, A. Delgado, V. Sanchez Gimenez, M. David, G. Sadowski, R. L. Smart, A. Masip, Laia Casamiquela, R. Messineo, R. Mor, J. Bakker, C. Dolding, J. M. Martín-Fleitas, S. Diakite, Coryn A. L. Bailer-Jones, D. Souami, P. Madrero Pardo, Martin A. Barstow, David Teyssier, Ummi Abbas, Jesus Salgado, Paolo Tanga, A. Burlacu, O. Vanel, Ulrike Heiter, Daniel Hestroffer, Sebastian L. Hidalgo, H. E. Delgado, Alberto Krone-Martins, C. Robin, Kevin Benson, Christos Siopis, S. Managau, P. Burgess, Tomaz Zwitter, M. M. S. Marcos Santos, S. Cowell, J. L. Halbwachs, Xavier Luri, Antti Penttilä, R. Geyer, Minia Manteiga, Yassine Damerdji, Nigel Hambly, S. Bartolomé, J. Álvarez Cid-Fuentes, P. Osborne, J. Juaristi Campillo, Mark Taylor, Richard I. Anderson, Y. Le Fustec, Thierry Morel, T. Cornez, Krzysztof A. Rybicki, L. Pulone, N. Bauchet, Pierre Kervella, C. Zurbach, Alfred Castro-Ginard, Frédéric Arenou, P. Ramos, Robert G. Mann, Annie C. Robin, J. C. Segovia, M. Barros, Hector Canovas, D. L. Harrison, Y. Lasne, L. Noval, David Hobbs, E. F. del Peloso, P. Castro Sampol, Yves Fremat, F. De Luise, Daniel Michalik, P. J. Richards, L. Karbevska, N. Hładczuk, K. Kruszyńska, T. Boch, Sofia Randich, A. G. A. Brown, C. Pagani, L. Martin Polo, M. Ramos-Lerate, Krzysztof Nienartowicz, Eduard Masana, E. Racero, E. Fraile, Marc Audard, N. Robichon, Luciana Bianchi, G. Gracia-Abril, R. Santoveña, R. Haigron, N. Unger, Jérôme Berthier, Despina Hatzidimitriou, R. Gutiérrez-Sánchez, M. Fabrizio, I. Gonzalez-Santamaria, A. Dapergolas, P. Panuzzo, Benoit Carry, Francesca Figueras, R. Blomme, Elmé Breedt, D. Munoz, Diego Bossini, G. Busso, D. Katz, Simon Hodgkin, Ennio Poretti, N. Brouillet, Marco Castellani, Nicholas Rowell, Arnaud Siebert, M. Romero-Gómez, Shay Zucker, W. van Reeven, A. Kochoska, G. Giuffrida, Eva Sciacca, T. Carlucci, L. M. Sarro, M. I. Carnerero, Amina Helmi, D. Garabato, B. Holl, Michele Bellazzini, L. Rohrbasser, Teresa Antoja, J. Torra, Thomas Hilger, Pedro García-Lario, Gérard Jasniewicz, Enrique Solano, S. G. Baker, W. J. Cooper, F. Royer, S. Accart, George M. Seabroke, João Alves, Emese Plachy, C. Nicolas, Silvio Leccia, N. Cheek, Uwe Lammers, Ramachrisna Teixeira, Techniche Universtât Desden, 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, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lund Observatory, Lund University [Lund], Zentrum für astronomie, Universität Heidelberg [Heidelberg], Department of nuclear medicine, Haukeland University Hospital, University of Bergen (UiB)-University of Bergen (UiB), Merck Serono S.A [Geneva Research Center], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Planetary-system research, Department of Physics, Particle Physics and Astrophysics, Gaia Collaboration, Unidad de Excelencia Científica María de Maeztu Instituto de Ciencias del Cosmos Universidad de Barcelona, MDM-2014-0369, Centro de Excelencia Científica Severo Ochoa, Instituto de Ciencias del Cosmos de la Universidad de Barcelona, SEV2015-0493, Deliste, J. B. [0000-0001-5844-9888], Sozzeti, A. [0000-0002-7504-365X], Forderung der wissenschaftlichen Forschung (FWF), Belgian federal Science Policy Office (BELSPO), Hertha Firnberg Programme, Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Comite Francais d'Evaluation de la Cooperation Universitaire et Scientifique avec le Bresil (COFECUB), National Natural Science Foundation of China (NSFC), China Scholarship Council (CSC), European Commission (EC), European Research Council (ERC), Hungarian National Research, Development, and Innovation Office (NKFIH), Science Foundation Ireland (SFI), Israel Science Foundation (ISF), Agenzia Spaziale Italiana (ASI), Istituto Nazionale di Astrofisica (INAF), Netherlands Research School for Astronomy (NOVA), Fundacao para a Ciencia e a Tecnologia (FCT), Agencia Estatal de Investigación (AEI), European Space Agency (ESA), Centre National D'Etudes Spatiales (CNES), Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR), Narodowe Centrum Nauki (NCN), Slovenian Research Agency, Swedish National Space Agency (SNSA), United Kingdom Science and Technology Facilities Council (STFC), Universitat de Barcelona (UB), Generalitat de Catalunya, Xunta de Galicia, Universidad de Cantabria, ITA, European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economía y Competitividad (España), Astronomy, and Kapteyn Astronomical Institute
Subjects: Data Analysis, Solar System, Astronomy, kinematics and dynamics, virgo cluster, Astrophysics, 01 natural sciences, bar, Astronomi, astrofysik och kosmologi, large-magellanic-cloud, Methods, Astronomy, Astrophysics and Cosmology, 010303 astronomy & astrophysics, Physics, Astrophysics of Galaxies, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Astrometry, VIRGO CLUSTER, Kinematics and Dynamics, Amplitude, kinematics, Physical Sciences, MILKY-WAY, astrometry, Galaxy: kinematics and dynamics, PROPER MOTION, Proper motion, perturbation, proper motions, reference systems, methods: data analysis, Astrophysics - Astrophysics of Galaxies, FOS: Physical sciences, Context (language use), proper motion, Astronomy & Astrophysics, MASS, Computer Science::Digital Libraries, Gravitational potential, Acceleration, Settore FIS/05 - Astronomia e Astrofisica, 0103 physical sciences, data analysis [methods], Vector spherical harmonics, KINEMATICS, distance, milky-way, Science & Technology, PERTURBATION, 010308 nuclear & particles physics, Astronomy and Astrophysics, kinematics and dynamics [Galaxy], 115 Astronomy, Space science, Physics::History of Physics, BAR, Galaxy, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), DISTANCE, mass, LARGE-MAGELLANIC-CLOUD
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) x 10(-10) m s(-2) (or 7.33 +/- 0.51 km s(-1) Myr-1) towards alpha = 269.1 degrees +/- 5.4 degrees, delta = -31.6 degrees +/- 4.1 degrees, corresponding to a proper motion amplitude of 5.05 +/- 0.35 mu as 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 mu as yr(-1).
Published: 2020
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14. AU Pegasi revisited: period evolution and orbital elements of a peculiar Type II Cepheid

Author: Laszlo Szabados and G. Csörnyei
Subjects: Orbital elements, Physics, Type II Cepheid, Period (periodic table), 010308 nuclear & particles physics, Cepheid variable, Diagram, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Cosmology, Radial velocity, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Tidal force, sense organs, skin and connective tissue diseases, 010303 astronomy & astrophysics
Abstract: New analysis on the period changes of Type II Cepheid AU Peg is presented. The available recent photometric measurements were collected and analysed with various methods. The period has been found to be constant for certain time intervals, although increasing in overall, in contrast with the previous expectations, which suggested the period change to reverse. Superimposed on overall period change, a formerly unknown periodic behaviour has been found in the $O-C$ diagram of AU Peg, which cannot be matched to the radial velocity variations. Since the Cepheid is a member of a binary system, it is probable that the unusual period change is in connection with the companion's tidal force. The orbital elements of the binary system involving AU Peg have been also revised., Comment: 8 pages, 8 figures, accepted for publication in Astrophysics and Space Science
Published: 2019
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15. Gaia Data Release 2 All-sky classification of high-amplitude pulsating stars

Author: S. Regibo, J. De Ridder, Vincenzo Ripepi, László Molnár, Leanne P. Guy, Lorenzo Rimoldini, Laurent Eyer, D. Teyssier, Maroussia Roelens, O. Marchal, L. M. Sarro, K. Nienartowicz, Nami Mowlavi, B. Holl, G. Jevardat de Fombelle, Thomas Lebzelter, Emese Plachy, Roberto Molinaro, Gisella Clementini, Marc Audard, Alessia Garofalo, M. López, D. W. Evans, I. Lecoeur-Taïbi, Laszlo Szabados, Attila Juhasz, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Brightness, OGLE COLLECTION, Cepheid variable, media_common.quotation_subject, variables, FOS: Physical sciences, VARIABLE STARS, Cepheids -stars, Astrophysics, RR Lyrae variable, Astronomy & Astrophysics, 01 natural sciences, Computer Science::Digital Libraries, variables: RR Lyrae [stars], 0103 physical sciences, data analysis [methods], general -stars, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Fourier series, Solar and Stellar Astrophysics (astro-ph.SR), variables: delta Scuti [stars], CEPHEIDS, media_common, [PHYS]Physics [physics], Physics, RR Lyrae, Science & Technology, catalogs -methods, data analysis -stars, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, delta Scutistars, CATALOG, Physics::History of Physics, Random forest, Stars, variables: Cepheids [stars], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sky, variables: general [stars], Physical Sciences, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Classifier (UML), catalogs
Abstract: More than half a million of the 1.69 billion sources in Gaia Data Release 2 (DR2) are published with photometric time series that exhibit light variations during the 22 months of observation. An all-sky classification of common high-amplitude pulsators (Cepheids, long-period variables, Delta Scuti / SX Phoenicis, and RR Lyrae stars) is provided for stars with brightness variations greater than 0.1 mag in G band. A semi-supervised classification approach was employed, firstly training multi-stage random forest classifiers with sources of known types in the literature, followed by a preliminary classification of the Gaia data and a second training phase that included a selection of the first classification results to improve the representation of some classes, before the improved classifiers were applied to the Gaia data. Dedicated validation classifiers were used to reduce the level of contamination in the published results. A relevant fraction of objects were not yet sufficiently sampled for reliable Fourier series decomposition, consequently classifiers were based on features derived from statistics of photometric time series in the G, BP, and RP bands, as well as from some astrometric parameters. The published classification results include 195,780 RR Lyrae stars, 150,757 long-period variables, 8550 Cepheids, and 8882 Delta Scuti / SX Phoenicis stars. All of these results represent candidates whose completeness and contamination are described as a function of variability type and classification reliability. Results are expressed in terms of class labels and classification scores, which are available in the vari_classifier_result table of the Gaia archive., Comment: 21 pages, 33 figures, with minor revisions, in press (Astronomy & Astrophysics)
Published: 2019
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16. Gaia Data Release 2. Specific characterisation and validation of all-sky Cepheids and RR Lyrae stars

Author: G. Jevardat de Fombelle, S. Regibo, B. Holl, J. De Ridder, M. Riello, Laszlo Szabados, Vincenzo Ripepi, Gisella Clementini, Leanne P. Guy, Marc Audard, Alessia Garofalo, O. Marchal, L. M. Sarro, D. W. Evans, T. Muraveva, I. Musella, Lorenzo Rimoldini, Nami Mowlavi, I. Lecoeur-Taïbi, Silvio Leccia, Roberto Molinaro, K. Nienartowicz, Laurent Eyer, Marcella Marconi, Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: stars, Cepheid variable, media_common.quotation_subject, variables, oscillations -stars, FOS: Physical sciences, Context (language use), Astrophysics, Cepheids -stars, RR Lyrae variable, RR Lyrae -methods, 01 natural sciences, data analysis -Galaxy, 0103 physical sciences, general -stars, structure, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), media_common, Dwarf galaxy, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Astronomy and Astrophysics, Light curve, Photometry (astronomy), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sky, Globular cluster, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The Gaia second Data Release (DR2) presents a first mapping of full-sky RR Lyrae stars and Cepheids observed by the spacecraft during the initial 22 months of science operations. The Specific Object Study (SOS) pipeline, developed to validate and fully characterise Cepheids and RR Lyrae stars (SOS Cep&RRL) observed by Gaia, has been presented in the documentation and papers accompanying the Gaia first Data Release. Here we describe how the SOS pipeline was modified to allow for processing the Gaia multiband (G, G_BP and G_RP) time series photometry of all-sky candidate variables and produce specific results for confirmed RR Lyrae stars and Cepheids that are published in the DR2 catalogue. The SOS Cep&RRL processing uses tools such as the period-amplitude and the period-luminosity relations in the G band. For the analysis of the Gaia DR2 candidates we also used tools based on the G_BP and G_RP photometry, such as the period-Wesenheit relation in (G,G_RP). Multiband time series photometry and characterisation by the SOS Cep&RRL pipeline are published in Gaia DR2 for 150,359 such variables (9,575 classified as Cepheids and 140,784 as RR Lyrae stars) distributed all over the sky. The sample includes variables in 87 globular clusters and 14 dwarf galaxies. To the best of our knowledge, as of 25 April 2018, variability of 50,570 of these sources (350 Cepheids and 50,220 RR Lyrae stars) is not known in the literature, hence likely they are new discoveries by Gaia. An estimate of the interstellar absorption is published for 54,272 fundamental-mode RR Lyrae stars from a relation based on the G-band amplitude and the pulsation period. Metallicities derived from the Fourier parameters of the light curves are also released for 64,932 RR Lyrae stars and 3,738 fundamental-mode classical Cepheids with period shorter than 6.3 days., 46 pages, 46 figures, 5 tables. Accepted for publication in Astronomy & Astrophysics
Published: 2019
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17. Gaia Data Release 2

Author: H. E. Huckle, F. Riclet, R. Buzzi, D. J. Marshall, Deborah Busonero, Michael Davidson, C Boeche, Sergio Messina, F. X. Pineau, G. Jasniewicz, L. Balaguer-Núñez, C. A. L. Bailer-Jones, L. Chaoul, J. L. Halbwachs, D. Teyssier, A. F. Lanza, Alberto Vecchiato, Shay Zucker, Francois Taris, Conny Aerts, L. Pulone, Mario Gai, L. M. Sarro, Frédéric Arenou, Á. L. Juhász, Alessandro Bressan, Joao Alves, Morgan Fouesneau, David Hobbs, Yves Fremat, L. Ruiz-Dern, A. Hutton, Sofia Randich, Gerry Gilmore, D. Garabato, Leanne P. Guy, J. González-Núñez, M. Weiler, H. Steidelmüller, D. de Martino, M. A. Álvarez, Vincenzo Ripepi, G. Gracia-Abril, Uwe Lammers, P. de Laverny, G. Sadowski, Nicolas Mary, Bengt Edvardsson, Laszlo Szabados, Łukasz Wyrzykowski, David Barrado, Alberto Cellino, Damien Ségransan, T Roegiers, Olivier Wertz, A. Recio-Blanco, Sergei A. Klioner, J. Durán, A. Panahi, A. Karampelas, Alex Lobel, J.-L. Bassilana, H. Voss, Sven Zschocke, A. Bombrun, F. De Angeli, Toni Santana-Ros, J. C. Segovia, D. Vicente, S. Blanco-Cuaresma, A. G. Butkevich, M. Riello, Amina Helmi, J. Bakker, J. Souchay, A. Kewley, R Alvarez, Daniel Hestroffer, Sergey E. Koposov, Tsevi Mazeh, Maria Süveges, F. F. Suess, P. Drazinos, B. Holl, H. Ziaeepour, T. Wevems, Eva Sciacca, P. Esquej, A. Gueguen, J. Heu, R. Geyer, J. Fernández-Hernández, E. Licata, Laurent Galluccio, J. Cuypers, Peter G. Jonker, Ummi Abbas, Elena Pancino, Jean Surdej, E. Anglada Varela, Michele Bellazzini, Teresa Antoja, Martin A. Barstow, László Molnár, Isabella Pagano, E. Solano, E. Brugaletta, P. Koubsky, Paolo Tanga, Alberto Krone-Martins, M. Clotet, Nigel Hambly, R. L. Smart, Paolo Giacobbe, Simchon Faigler, G. Giuffrida, Aldo Dell'Oro, Yveline Lebreton, Stefano Bertone, Mario G. Lattanzi, Paul S. Barklem, D. Tapiador, Patrick Charlot, A. H. Andrei, Luciano Nicastro, S. Managau, Lorenzo Rimoldini, Mario Di Martino, Paolo Montegriffo, A. Abreu Aramburu, O. Marchal, Marcella Marconi, K. Janßen, K. Findeisen, Xavier Luri, A. Berihuete, M. Schultheis, P. Di Matteo, R. Mor, C. Barata, A. Mora, W. van Reeven, Mikael Granvik, M. Barros, Carine Babusiaux, A. G. A. Brown, Mark Taylor, Y. Le Fustec, T. Lebzelter, Nami Mowlavi, O. L. Creevey, F. Barblan, Thierry Morel, Timo Prusti, A. Riva, S. Girona, S. Liao, Viktor Votruba, Frédéric Royer, Laurent Chemin, G. Altavilla, A. M. Piersimoni, Davide Massari, Marco Delbo, S. Diakite, V. Valette, N. Bach, H. Lenhardt, André Moitinho, Christophe Barache, S. Galleti, Michał Pawlak, A. Yoldas, Harry Enke, Rosanna Sordo, A. Jean-Antoine-Piccolo, Patrice David, Giacomo Cannizzaro, W. Löffler, J. Torra, Tristan Cantat-Gaudin, Marc Audard, D. Katz, Jose M Hernandez, Gijs Nelemans, S. Ragaini, P. Osborne, D. Terrett, A. J. Falcão, D. L. Harrison, G. Plum, R. G. Mann, Ulrike Heiter, Carla Cacciari, Gal Matijevic, J. M. Petit, A. Titarenko, Despina Hatzidimitriou, Juan Zorec, Angela Bragaglia, Nicholas Rowell, Annie C. Robin, Mario David, Tri L. Astraatmadja, Giovanni Comoretto, F. Julbe, Derek W. Morris, R. Drimmel, F. García-Sedano, A. Dapergolas, L. Noval, Mike Smith, Grigori Fedorets, H. Palacin, L. Bramante, D. Molina, Jesus Salgado, C. Dolding, M. Vaillant, Daniel Michalik, H. I. Siddiqui, Minia Manteiga, P. J. Richards, D. Barbato, A. Fonti, Raphael Guerra, J. J. González-Vidal, E. del Pozo, Mariateresa Crosta, M. Žerjal, F. Torra Clotet, C. Diener, M. Hauser, G. Walmsley, Sonia Nieto, I. Bellas-Velidis, T. Boch, Antonella Vallenari, M. Segol, S. Voutsinas, F. Leroux, A. F. Mulone, Pierre Fernique, Céline Reylé, P. Panuzzo, W. Hofmann, S. Bouquillon, F. Crifo, S. Cowell, Ana Ulla, Benoit Carry, C. Ordenovic, F. Pailler, E. Utrilla, Dimitri Pourbaix, A. Hypki, Stefan Jordan, T. Carlucci, Gráinne Costigan, Alfred Castro-Ginard, C. Fabre, C. Crowley, R. Borrachero, Sébastien Lambert, J. H. J. de Bruijne, D. W. Evans, C. Turon, T. Brüsemeister, F. De Luise, R. Haigron, Carme Jordi, G. Marschalkó, C. von Essen, C. Pagani, Katrien Kolenberg, M. van Leeuwen, N. R. Millar, Gisella Clementini, A. de Torres, Ugo Becciani, S. Marinoni, Geraldine Bourda, A. F. Silva, L. Eyer, Misha Haywood, C. Fabricius, Krzysztof Nienartowicz, Miguel García-Torres, S. Regibo, P. Gavras, Gábor Marton, Elisa Distefano, A. Guerrier, H. E. P. Lindstrøm, N. A. Walton, N. Brouillet, G. Eynard Bontemps, T. A. Lister, F. A. Jansen, Ruth Carballo, Steve Vogt, J. M. Carrasco, G. Mantelet, M. Romero-Gómez, Ramachrisna Teixeira, Kjell Eriksson, A. Kochoska, Johannes Sahlmann, Joakim Klar, R. Gutiérrez-Sánchez, Ilaria Musella, L. Palaversa, Karri Muinonen, J. M. Martín-Fleitas, T. Sagristà Sellés, Marco Castellani, Y. Viala, Laia Casamiquela, R. Messineo, Eduard Masana, R. de Souza, H. Stoev, L. Siltala, B. Frezouls, E. Szegedi-Elek, Tomaz Zwitter, G. Kordopatis, C. Ducourant, Tatiana Muraveva, P. Burgess, J. De Ridder, E. Salguero, A. Burlacu, I-C. Shih, U. Stampa, V. Icardi, Iain A. Steele, Alessandro Sozzetti, M. Kontizas, Roberto Molinaro, F. Solitro, H. E. Delgado, G. Holland, J.-B. Lavigne, Andreas Korn, M. Biermann, E. Fraile, M. Fabrizio, Francesca Figueras, R. Blomme, P. Teyssandier, Elisabetta Caffau, G. Busso, Maroussia Roelens, Maarten A. Breddels, Simon Hodgkin, Luciana Bianchi, Olivier Bienaymé, Silvio Leccia, C. Le Poncin-Lafitte, Morgan Fraser, M. Ramos-Lerate, M. Gomes, N. Cheek, J. Osinde, Jérôme Berthier, Kevin Benson, Christos Siopis, P. Balm, E. Gosset, Yassine Damerdji, Richard I. Anderson, C. Zurbach, Jonas Debosscher, G. Cocozza, William O'Mullane, Andrea Chiavassa, F.E. van Leeuwen, Diego Bossini, Federica Spoto, G. Jevardat de Fombelle, Nicoletta Sanna, J. Guiraud, G. Tauran, K. W. Smith, E. Poujoulet, Mark Cropper, Z. Kostrzewa-Rutkowska, F. Glass, J. Gerssen, Thomas Hilger, C.A. Stephenson, D. Ordóñez-Blanco, Andrej Prsa, M. Sarasso, E. Kontizas, Luciana Federici, Paul J. McMillan, Nicolas Rambaux, Ludovic Delchambre, M. Garcia-Reinaldos, T. Pauwels, M. Farràs Casas, S. Bartholomé Muñoz, E. Livanou, E. Van Hemelryck, Roberto Morbidelli, R. Kohley, A. Garofalo, Jovan Veljanoski, Jon Marchant, Jordi Portell, Ulrich Bastian, M. Lopez, Bernardino Arcay, H. Savietto, Alessandro Spagna, A. C. Lanzafame, Beatrice Bucciarelli, C. Panem, Carlos Dafonte, Y. Lasne, P. Sartoretti, E. Racero, William Thuillot, A. Gavel, J. Castañeda, Gaetano Valentini, A. Rivard, E. Poggio, N. Garralda, R. De March, S. G. Baker, S. Accart, M. Altmann, F. Filippi, George M. Seabroke, F. Thévenin, A. van Elteren, Emese Plachy, Lennart Lindegren, Isabelle Lecoeur-Taïbi, Guy Rixon, S Uzzi, M Vaschetto, Francois Mignard, E. Antiche, P. M. Marrese, N. Leclerc, Caroline Soubiran, Rene Andrae, A. Delgado, and Rossella Cancelliere
Subjects: Physics, 010504 meteorology & atmospheric sciences, Astronomy, Astronomy and Astrophysics, galaxies: dwarf, Astrophysics, Astrometry, globular clusters: general, 01 natural sciences, Settore FIS/05 - Astronomia e Astrofisica, Space and Planetary Science, 0103 physical sciences, Local Group, astrometry, High Energy Physics, Galaxy: kinematics and dynamics, astrometry, globular clusters: general, galaxies: dwarf, Local Group, errata, addenda, Galaxy: kinematics and dynamics, addenda, 010303 astronomy & astrophysics, Data release, Astrophysique, errata, 0105 earth and related environmental sciences
Abstract: 0, info:eu-repo/semantics/published
Published: 2020
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18. Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2 -- II. Resolved common proper motion pairs

Author: Laszlo Szabados, Pierre Kervella, Wolfgang Gieren, Frédéric Arenou, Antoine Mérand, Nicolas Nardetto, Grzegorz Pietrzyński, Nancy Remage Evans, and Alexandre Gallenne
Subjects: Physics, education.field_of_study, Nebula, Proper motion, 010308 nuclear & particles physics, Cepheid variable, Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrometry, Astrophysics, RR Lyrae variable, Orbital period, 01 natural sciences, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Context. The multiplicity of classical Cepheids (CCs) and RR Lyrae stars (RRLs) is still imperfectly known, particularly for RRLs. Aims. In order to complement the close-in short orbital period systems presented in Paper I, our aim is to detect the wide, spatially resolved companions of the targets of our reference samples of Galactic CCs and RRLs. Methods. Angularly resolved common proper motion pairs were detected using a simple progressive selection algorithm to separate the most probable candidate companions from the unrelated field stars. Results. We found 27 resolved, high probability gravitationally bound systems with CCs out of 456 examined stars, and one unbound star embedded in the circumstellar dusty nebula of the long-period Cepheid RS Pup. We found seven spatially resolved, probably bound systems with RRL primaries out of 789 investigated stars, and 22 additional candidate pairs. We report in particular new companions of three bright RRLs: OV And (companion of F4V spectral type), RR Leo (M0V), and SS Oct (K2V). In addition, we discovered resolved companions of 14 stars that were likely misclassified as RRLs. Conclusions. The detection of resolved non-variable companions around CCs and RRLs facilitates the validation of their Gaia DR2 parallaxes. The possibility to conduct a detailed analysis of the resolved coeval companions of CCs and old population RRLs will also be valuable to progress on our understanding of their evolutionary path., Comment: 42 pages, published in Astronomy & Astrophysics
Published: 2019
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19. The zinc finger protein 3 of Arabidopsis thaliana regulates vegetative growth and root hair development

Author: Dániel Benyó, Emese Bató, Dóra Faragó, Gábor Rigó, Ildikó Domonkos, Nitin Labhane, Laura Zsigmond, Melvin Prasad, István Nagy, and László Szabados
Subjects: Arabidopsis thaliana, zinc finger protein 3, gene overexpression, gene silencing, plant development, root hair, Plant culture, SB1-1110
Abstract: IntroductionZinc finger protein 3 (ZFP3) and closely related C2H2 zinc finger proteins have been identified as regulators of abscisic acid signals and photomorphogenic responses during germination. Whether ZFP3 and related ZFP factors regulate plant development is, however, not known.ResultsZFP3 overexpression reduced plant growth, limited cell expansion in leaves, and compromised root hair development. The T-DNA insertion zfp3 mutant and transgenic lines with silenced ZFP1, ZFP3, ZFP4, and ZFP7 genes were similar to wild-type plants or had only minor differences in plant growth and morphology, probably due to functional redundancy. RNAseq transcript profiling identified ZFP3-controlled gene sets, including targets of ABA signaling with reduced transcript abundance. The largest gene set that was downregulated by ZFP3 encoded regulatory and structural proteins in cell wall biogenesis, cell differentiation, and root hair formation. Chromatin immunoprecipitation confirmed ZFP3 binding to several target promoters.DiscussionOur results suggest that ZFP3 and related ZnF proteins can modulate cellular differentiation and plant vegetative development by regulating the expression of genes implicated in cell wall biogenesis.
Published: 2024
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20. Gaia's Cepheids and RR Lyrae Stars and Luminosity Calibrations Based on Tycho-Gaia Astrometric Solution

Author: Laszlo Szabados, L. M. Sarro, Marcella Marconi, Laurent Eyer, Roberto Molinaro, Richard I. Anderson, Vincenzo Ripepi, Xavier Luri, Tatiana Muraveva, Lorenzo Rimoldini, Ilaria Musella, Alessia Garofalo, Gisella Clementini, and M. Palmer
Subjects: Absolute magnitude, Physics, 010504 meteorology & atmospheric sciences, Cepheid variable, QC1-999, FOS: Physical sciences, Astrophysics, RR Lyrae variable, 01 natural sciences, Photometry (optics), Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, Parallax, 010303 astronomy & astrophysics, Data release, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract: Gaia Data Release 1 contains parallaxes for more than 700 Galactic Cepheids and RR Lyrae stars, computed as part of the Tycho-Gaia Astrometric Solution (TGAS). We have used TGAS parallaxes, along with literature ($V, I, J, {K_\mathrm{s}}, W_1$) photometry and spectroscopy, to calibrate the zero point of the Period-Luminosity and Period-Wesenheit relations of classical and type II Cepheids, and the near-infrared Period-Luminosity, Period-Luminosity-Metallicity and optical Luminosity-Metallicity relations of RR Lyrae stars. In this contribution we briefly summarise results obtained by fitting these basic relations adopting different techniques that operate either in parallax or distance (absolute magnitude) space., 5 pages, 4 figures, proceedings for the 22nd Los Alamos Stellar Pulsation Conference Series Meeting "Wide field variability surveys: a 21st-century perspective", held in San Pedro de Atacama, Chile, Nov. 28 - Dec. 2, 2016
Published: 2017

21. Analysis of the possible Blazhko-effect Cepheid V473 Lyrae

Author: Laszlo Szabados, R. J. Dukes, Á. Győrffy, Róbert Szabó, and László Molnár
Subjects: Physics, 010504 meteorology & atmospheric sciences, Cepheid variable, Blazhko effect, Phase (waves), Astronomy and Astrophysics, Astrophysics, Fourier spectrum, RR Lyrae variable, 01 natural sciences, Amplitude modulation, Amplitude, Space and Planetary Science, 0103 physical sciences, Modulation (music), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: V473 Lyrae is a peculiar Galactic Cepheid, showing strong amplitude modulation that resembles the Blazhko-effect observed in RR Lyrae stars. We collected data spanning several modulation cycles and started a detailed analysis. The first results indicate that the star shows both amplitude and phase modulations with an average period of 1204 days, but both the cycle length and the strength of the modulation are subjected to considerable variations. A possible quintuplet component in the Fourier spectrum and additional period changes were also detected. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2013
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22. Toward a renewed Galactic Cepheid distance scale from Gaia and optical interferometry

Author: Alexandre Gallenne, Wolfgang Gieren, Richard I. Anderson, Pierre Kervella, J. Breitfelder, Grzegorz Pietrzyński, Simon Borgniet, Howard E. Bond, Nicolas Nardetto, Boris Trahin, Antoine Mérand, and Laszlo Szabados
Subjects: Length scale, Physics, Infrared excess, 010308 nuclear & particles physics, Cepheid variable, QC1-999, FOS: Physical sciences, Observable, Astrophysics, Velocimetry, Effective temperature, 01 natural sciences, Interferometry, Photometry (astronomy), Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, 14. Life underwater, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Through an innovative combination of multiple observing techniques and mod- eling, we are assembling a comprehensive understanding of the pulsation and close environment of Cepheids. We developed the SPIPS modeling tool that combines all observables (radial velocimetry, photometry, angular diameters from interferometry) to derive the relevant physical parameters of the star (effective temperature, infrared ex- cess, reddening,...) and the ratio of the distance and the projection factor d/p. We present the application of SPIPS to the long-period Cepheid RS Pup, for which we derive p = 1.25 +/- 0.06. The addition of this massive Cepheid consolidates the existing sample of p-factor measurements towards long-period pulsators. This allows us to conclude that p is constant or mildly variable around p = 1.29 +/- 0.04 (+/-3%) as a function of the pulsation period. The forthcoming Gaia DR2 will provide a considerable improvement in quantity and accuracy of the trigonometric parallaxes of Cepheids. From this sample, the SPIPS modeling tool will enable a robust calibration of the Cepheid distance scale., 5 pages, 4 figures, proceedings of the 22nd Los Alamos Stellar Pulsation Conference "Wide-field variability surveys: a 21st-century perspective" held in San Pedro de Atacama, Chile, Nov. 28-Dec. 2, 2016
Published: 2017

23. Observational calibration of the projection factor of Cepheids

Author: Pierre Kervella, Boris Trahin, Howard E. Bond, Alexandre Gallenne, Laszlo Szabados, Antoine Mérand, Joanne Breitfelder, Julien Dailloux, Richard I. Anderson, Pascal Fouqué, Wolfgang Gieren, Nicolas Nardetto, Grzegorz Pietrzyński
Published: 2017
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24. Observational calibration of the projection factor of Cepheids

Author: Alexandre Gallenne, Richard I. Anderson, Pierre Kervella, J. Breitfelder, Howard E. Bond, Pascal Fouqué, Julien Dailloux, Laszlo Szabados, Grzegorz Pietrzyński, Wolfgang Gieren, Nicolas Nardetto, Antoine Mérand, Boris Trahin, Laboratoire Franco-Chilien d'Astronomie (LFCA), Centre National de la Recherche Scientifique (CNRS)-Universidad de Concepción [Chile]-Pontificia Universidad Católica de Chile (UC)-Universidad de Chile-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pennsylvania State University (Penn State), Penn State System, European Southern Observatory (ESO), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Johns Hopkins University (JHU), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Universidad de Concepción [Chile], 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), Copernicus Astronomical Center of the Polish Academy of Sciences (CAMK), Polish Academy of Sciences (PAN), ANR-15-CE31-0012,UnlockCepheids,Libérer le potentiel des Céphéides comme étalons primaires de distance(2015), European Project: 695099,CEPBIN, Universidad de Chile = University of Chile [Santiago] (UCHILE)-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Concepción - University of Concepcion [Chile], Université de Genève = University of Geneva (UNIGE), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción - University of Concepcion [Chile], Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción [Chile]-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Chile, Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (... - 2019) (UNS), and Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Length scale, Nebula, 010308 nuclear & particles physics, Cepheid variable, Stars: variables: Cepheids, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Stars: individual: RS Pup, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Photometry (optics), Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Long period, 0103 physical sciences, Cosmology: distance scale, Techniques: interferometric, Stars: distances, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Techniques: photometric
Abstract: The projection factor (p-factor) is an essential component of the classical Baade-Wesselink (BW) technique, that is commonly used to determine the distances to pulsating stars. It is a multiplicative parameter used to convert radial velocities into pulsational velocities. As the BW distances are linearly proportional to the p-factor, its accurate calibration for Cepheids is of critical importance for the reliability of their distance scale. We focus on the observational determination of the p-factor of the long-period Cepheid RS Pup (P = 41.5 days). This star is particularly important as this is one of the brightest Cepheids in the Galaxy and an analog of the Cepheids used to determine extragalactic distances. An accurate distance of 1910 +/- 80 pc (+/- 4.2%) has recently been determined for RS Pup using the light echoes propagating in its circumstellar nebula. We combine this distance with new VLTI/PIONIER interferometric angular diameters, photometry and radial velocities to derive the p-factor of RS Pup using the code Spectro-Photo-Interferometry of Pulsating Stars (SPIPS). We obtain p = 1.250 +/- 0.064 (+/-5.1%), defined for cross-correlation radial velocities. Together with measurements from the literature, the p-factor of RS Pup confirms the good agreement of a constant p = 1.293 +/- 0.039 (+/-3.0%) model with the observations. We conclude that the p-factor of Cepheids is constant or mildly variable over a broad range of periods (3.7 to 41.5 days)., 17 pages, 15 figures, Astronomy & Astrophysics, in press
Published: 2017
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25. Binarity among Cepheids in the Magellanic Clouds

Author: Laszlo Szabados and Dóra Nehéz
Subjects: Physics, Radial velocity, Stars, Space and Planetary Science, Cepheid variable, Astronomy and Astrophysics, Astrophysics, Large Magellanic Cloud, Amplitude ratio
Abstract: Spectroscopic binarity of the Cepheid variable HV914 in the Large Magellanic Cloud is pointed out from the published radial velocity observational data. The list of known binaries among Cepheid type variable stars in the Magellanic Clouds is published in tabular form. The census indicates a serious deficiency of Cepheids with known companions as compared with their Galactic counterparts, whose implications are also discussed. A particular amplitude ratio (A_{V_{rad}}/A_B) of individual Magellanic Cepheids is studied in order to select promising candidates of spectroscopic binaries worthy of thorough radial velocity studies.
Published: 2012
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26. Discovery of the spectroscopic binary nature of the Cepheids X Puppis and XX Sagittarii

Author: Aliz Derekas, Csaba Kiss, Laszlo Szabados, and P. Klagyivik
Subjects: Physics, Frequency of occurrence, Space and Planetary Science, Cepheid variable, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Solar and Stellar Astrophysics, Binary number, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Orbit (control theory), Stellar evolution, Astrophysics::Galaxy Astrophysics
Abstract: We present the analysis of photometric and spectroscopic data of two bright Galactic Cepheids, X Puppis and XX Sagittarii. Based on the available data in the literature as well as our own observations spanning 75 years, we conclude that both Cepheids belong to spectroscopic binary systems. However, the data are not sufficient to determine the orbital periods or other elements for the orbit. This discovery corroborates statements on the high frequency of occurrence of binaries among classical Cepheids, a fact to be taken into account when calibrating the period–luminosity relationship for Cepheids. The photometric data revealed that the pulsation period of X Pup is continuously increasing by P = 0.007 559 d century −1 , likely caused by stellar evolution. The pulsation period of XX Sgr turned out to be very stable over the last ∼100 years.
Published: 2012
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27. COMMISSION 30: RADIAL VELOCITIES

Author: Dainis Dravins, Stéphane Udry, Birgitta Nordström, Andrei Tokovinin, Francis C. Fekel, H. Levato, Dimitri Pourbaix, M. A. Smith, Guillermo Torres, E. V. Glushkova, and Laszlo Szabados
Subjects: Physics, Radial velocity, Stellar kinematics, Stars, Star cluster, Space and Planetary Science, Milky Way, Stellar dynamics, Astronomy, Astronomy and Astrophysics, Commission, Astrophysics, Exoplanet
Abstract: This report from Commission 30 covers the salient areas in which major progress has been made in the triennium covered by the present volume. The principal scientific areas are: The Milky Way, star clusters, spectroscopic binaries, extrasolar planets, pulsating stars and stellar oscillations. Following these, an account is given of the progress in techniques and methodology for radial velocity determinations. Finally, a summary is given of the progress made by the working groups of the Commission, followed by a list of key papers in the triennium. A more extensive report also covering extragalactic work, which due to unforeseen circumstances could not be included here, can be found at the web page of Commission 30 (http://www.iau.org/IAU/Organization/divcom/).
Published: 2011
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28. Multiplicity of Galactic Cepheids and RR Lyrae stars from Gaia DR2

Author: Nicolas Nardetto, Antoine Mérand, Wolfgang Gieren, Alexandre Gallenne, Paulina Karczmarek, Y. Proto, Grzegorz Pietrzyński, Nancy Remage Evans, Frédéric Arenou, Pierre Kervella, and Laszlo Szabados
Subjects: Physics, education.field_of_study, Proper motion, 010308 nuclear & particles physics, Cepheid variable, Population, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Astrometry, RR Lyrae variable, Orbital period, 01 natural sciences, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, education, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Classical Cepheids (CCs) and RR Lyrae stars (RRLs) are important classes of variable stars used as standard candles to estimate galactic and extragalactic distances. Their multiplicity is imperfectly known, particularly for RRLs. Astoundingly, to date only one RRL has convincingly been demonstrated to be a binary, TU UMa, out of tens of thousands of known RRLs. Our aim is to detect the binary and multiple stars present in a sample of Milky Way CCs and RRLs. In the present article, we combine the Hipparcos and Gaia DR2 positions to determine the mean proper motion of the targets, and we search for proper motion anomalies (PMa) caused by close-in orbiting companions. We identify 57 CC binaries from PMa out of 254 tested stars and 75 additional candidates, confirming the high binary fraction of these massive stars. For 28 binary CCs, we determine the companion mass by combining their spectroscopic orbital parameters and astrometric PMa. We detect 13 RRLs showing a significant PMa out of 198 tested stars, and 61 additional candidates. We determine that the binary fraction of CCs is likely above 80%, while that of RRLs is at least 7%. The newly detected systems will be useful to improve our understanding of their evolutionary states. The discovery of a significant number of RRLs in binary systems also resolves the long-standing mystery of their extremely low apparent binary fraction., 18 pages, 6 figures, Astronomy & Astrophysics, in press
Published: 2019
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29. V473 Lyr, a modulated, period-doubled Cepheid, and U TrA, a double-mode Cepheid observed by MOST

Author: Jason F. Rowe, Chris Cameron, Marcin Sokolowski, A. F. J. Moffat, B. Csák, Joshua Pepper, Slavek M. Rucinski, Ádám Sódor, Keivan G. Stassun, Jaymie M. Matthews, Phillip A. Reed, Werner W. Weiss, Lech Mankiewicz, Á. Dózsa, A. Cwiek, David B. Guenther, Laszlo Szabados, András Pál, Aliz Derekas, Karen A. Collins, Joseph E. Rodriguez, Bernard Heathcote, Terry Bohlsen, Nancy Remage Evans, Róbert Szabó, Emese Plachy, Robert J. Siverd, D. Sasselov, Paul Luckas, M. Skarka, Paulo Cacella, Noel D. Richardson, József Kovács, A. A. Henden, Gy. M. Szabó, Aleksander Filip Żarnecki, Katrien Kolenberg, Rainer Kuschnig, and László Molnár
Subjects: Period-doubling bifurcation, Physics, 010308 nuclear & particles physics, Cepheid variable, Overtone, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, 01 natural sciences, Radial velocity, Photometry (optics), Amplitude, Spitzer Space Telescope, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Space-based photometric measurements first revealed low-amplitude irregularities in the pulsations of Cepheid stars, but their origins and how commonly they occur remain uncertain. To investigate this phenomenon, we present MOST space telescope photometry of two Cepheids. V473 Lyrae is a second-overtone, strongly modulated Cepheid, while U Trianguli Australis is a Cepheid pulsating simultaneously in the fundamental mode and first overtone. The nearly continuous, high-precision photometry reveals alternations in the amplitudes of cycles in V473 Lyr, the first case of period doubling detected in a classical Cepheid. In U TrA, we tentatively identify one peak as the $f_X$ or 0.61-type mode often seen in conjunction with the first radial overtone in Cepheids, but given the short length of the data, we cannot rule out that it is a combination peak instead. Ground-based photometry and spectroscopy were obtained to follow two modulation cycles in V473 Lyr and to better specify its physical parameters. The simultaneous data yield the phase lag parameter (the phase difference between maxima in luminosity and radial velocity) of a second-overtone Cepheid for the first time. We find no evidence for a period change in U TrA or an energy exchange between the fundamental mode and the first overtone during the last 50 years, contrary to earlier indications. Period doubling in V473 Lyr provides a strong argument that mode interactions do occur in some Cepheids and we may hypothesise that it could be behind the amplitude modulation, as recently proposed for Blazhko RR Lyrae stars., Comment: 14 pages, 10 figures, accepted for publication in MNRAS. Data files can be found (temporarily) at http://konkoly.hu/~lmolnar/v473lyr_utra_data.zip
Published: 2016
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30. First observations of W Virginis stars with K2: detection of period doubling

Author: László Molnár, Laszlo Szabados, András Pál, Róbert Szabó, Radosław Smolec, P. Moskalik, M. I. Jurkovic, and Emese Plachy
Subjects: Physics, Period-doubling bifurcation, 010308 nuclear & particles physics, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Light curve, 01 natural sciences, Stars, Astrophysics - Solar and Stellar Astrophysics, Spitzer Space Telescope, Space and Planetary Science, Globular cluster, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 10. No inequality, Variation (astronomy), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present the first analysis of W Vir stars observed by the Kepler space telescope in the K2 mission. Clear cycle-to-cycle variation were detected in the light curves of KT Sco and the globular cluster member M80-V1. While the variations in the former star seems to be irregular on the short time scale of the K2 data, the latter appears to experience period doubling in its pulsation. Ground-based colour data confirmed that both stars are W Vir-type pulsators, while a comparison with historical photometric time-series data revealed drastic period changes in both stars. For comparison we reexamine ground-based observations of W Vir, the prototype of the class, and conclude that it shows period doubling instead of mode beating. These results support the notion that nonlinear dynamics plays an important role in the pulsation of W Virginis-type stars., Comment: 8 pages, 7 figures, accepted for publication in MNRAS
Published: 2016
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31. New homogeneous iron abundances of double-mode Cepheids from high-resolution echelle spectroscopy

Author: E. Poretti, Jozsef Vinko, Laszlo Szabados, K. Sziladi, and M. Kun
Subjects: Physics, Cepheid variable, Metallicity, Astrophysics (astro-ph), FOS: Physical sciences, High resolution, Astronomy and Astrophysics, Astrophysics, Spectral line, Stars, Space and Planetary Science, Homogeneous, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, Spectrograph, Astrophysics::Galaxy Astrophysics
Abstract: Aims: We define the relationship between the double-mode pulsation of Cepheids and metallicity in a more accurate way, determine the empirical metallicities of double-mode Cepheids from homogeneous, high-resolution spectroscopic data, and study of the period-ratio -- metallicity dependence. Methods: The high S/N echelle spectra obtained with the FEROS spectrograph were analyzed using a self-developed IRAF script, and the iron abundances were determined by comparing with synthetic spectra assuming LTE. Results: Accurate [Fe/H] values of 17 galactic beat Cepheids were determined. All these stars have solar or slightly subsolar metallicity. Their period ratio P1/P0 shows strong correlation with their derived [Fe/H] values. The corresponding period ratio -- metallicity relation has been evaluated., Comment: 10 pages, 7 figures, accepted in A&A
Published: 2007
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32. The 2004-2006 Outburst and Environment of V1647 Ori

Author: M. J. Vidal-Nunez, J. A. Acosta-Pulido, Laszlo Szabados, Arturo Manchado, József Benkő, M. Rácz, P. Székely, Mária Kun, Ágnes Kóspál, Péter Ábrahám, László L. Kiss, Attila Moór, M. Charcos-Llorens, Z. T. Kiss, C. Ramos Almeida, Sz. Csizmadia, R. Barrena Delgado, and M. Eredics
Subjects: Physics, Brightness, Nebula, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Light curve, Protoplanetary nebula, Luminosity, Stars, Emission nebula, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Line (formation)
Abstract: We studied the brightness and spectral evolution of the young eruptive star V1647 Ori during its recent outburst in the period 2004 February-2006 September. We performed a photometric follow-up in the bands V, RC, IC, J, H, and Ks, as well as visible and near-IR spectroscopy. The main results derived from combining our data with those published by other authors are as follows: the brightness of V1647 Ori stayed more than 4 mag above the preoutburst level until 2005 October, when it started a rapid fading. In the high state we found a periodic component in the optical light curves with a period of 56 days. The delay between variations of the star and variations in the brightness of clumps of nearby nebulosity corresponds to an angle of 61° ± 14° between the axis of the nebula and the line of sight. The overall appearance of the infrared and optical spectra did not change in the period 2004 March-2005 March, although a steady decrease of H I emission-line fluxes could be observed. In 2006 May, in the quiescent phase, the He I 1.083 μm line was observed in emission, contrary to its deep blueshifted absorption observed during the outburst. The J - H and H - Ks color maps of the infrared nebula reveal an envelope around the star whose largest extension is about 18'' (0.03 pc). The color distribution of the infrared nebula suggests reddening of the scattered light inside a thick circumstellar disk. Comparison of the Ks and Hα images of McNeil's Nebula, the conical nebulosity illuminated by V1647 Ori, shows that HH 22A, the Spitzer infrared source, and the bright clump C of the nebula may be unrelated objects. We show that the observed properties of V1647 Ori could be interpreted in the framework of the thermal instability models of Bell and coworkers. V1647 Ori might belong to a new class of young eruptive stars, defined by relatively short timescales, recurrent outbursts, a modest increase in bolometric luminosity and accretion rate, and an evolutionary state earlier than that of typical EXors.
Published: 2007
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33. Defining the instability strip of pulsating post-AGB binary stars from ASAS and NSVS photometry

Author: Gy. M. Szabó, Timothy R. Bedding, Laszlo Szabados, László L. Kiss, and Aliz Derekas
Subjects: Physics, Nebula, Brightness, Type II Cepheid, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Orbital period, Light curve, Stars, Space and Planetary Science, Binary star, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Instability strip, Astrophysics::Galaxy Astrophysics
Abstract: We analyse public domain time-series photometric observations of 30 known and candidate binary post-AGB stars for measuring pulsation and orbital periods. We derive periodicities for 17 stars for the first time in the literature. Besides identifying five new RV Tauri type pulsating variables (three with the RVb phenomenon, i.e. long-term changes of the mean brightness), we find multiply periodic (or possibly irregular) post-AGB stars on the two edges of the instability strip. The temperature dependence of the peak-to-peak light curve amplitudes clearly indicates the changes in excitation as post-AGB stars evolve through the strip. One object, the peculiar Type II Cepheid ST Pup, showed a period increase from 18.5 to 19.2 d, which is consistent with the known period fluctuations in the past. In HD 44179, the central star of the Red Rectangle nebula, we see very similar asymmetric light curve than was measured 10-15 years ago, suggesting a very stable circumstellar environment. In contrast to this, HD 213985 shows coherent but highly non-repetitive brightness modulation, indicating changes in the circumstellar cloud on a similar time-scale to the orbital period.
Published: 2007
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34. Observations of Cepheids with the MOST satellite: Contrast between Pulsation Modes

Author: A. F. J. Moffat, D. Sasselov, David B. Guenther, Werner W. Weiss, Laszlo Szabados, Slavek M. Rucinski, Aliz Derekas, Jaymie M. Matthews, Nancy Remage Evans, Jason F. Rowe, Róbert Szabó, C. Cameron, and Rainer Kuschnig
Subjects: Physics, 010308 nuclear & particles physics, Cepheid variable, Overtone, Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Light curve, 01 natural sciences, Instability, Stars, Quality (physics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Fourier series, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: The quantity and quality of satellite photometric data strings is revealing details in Cepheid variation at very low levels. Specifically, we observed a Cepheid pulsating in the fundamental mode and one pulsating in the first overtone with the Canadian MOST satellite. The 3.7-d period fundamental mode pulsator (RT Aur) has a light curve that repeats precisely, and can be modeled by a Fourier series very accurately. The overtone pulsator (SZ Tau, 3.1 d period) on the other hand shows light curve variation from cycle to cycle which we characterize by the variations in the Fourier parameters. We present arguments that we are seeing instability in the pulsation cycle of the overtone pulsator, and that this is also a characteristic of the O-C curves of overtone pulsators. On the other hand, deviations from cycle to cycle as a function of pulsation phase follow a similar pattern in both stars, increasing after minimum radius. In summary, pulsation in the overtone pulsator is less stable than that of the fundamental mode pulsator at both long and short timescales., accepted in MNRAS, 11 pages, 10 figures
Published: 2015

35. Transiting exoplanets from the CoRoT space mission{star}. XXVIII. CoRoT-33b, an object in the brown dwarf desert with 2:3 commensurability with its host star

Author: Sz. Csizmadia, Aviv Ofir, Artie P. Hatzes, S. Carpano, Aldo S. Bonomo, Tsevi Mazeh, Laszlo Szabados, E. W. Guenther, M. Ollivier, Alexandre Santerne, J. M. Almenara, Guillaume Hébrard, Anders Erikson, Pascal Bordé, Davide Gandolfi, Sylvio Ferraz-Mello, Roi Alonso, Rodrigo F. Díaz, Malcolm Fridlund, Hannu Parviainen, J. Schneider, S. Grziwa, P. Klagyivik, Annie Baglin, Martin Pätzold, Juan Cabrera, François Bouchy, Hans-Jörg Deeg, Daniel Rouan, Magali Deleuil, M. Tadeu dos Santos, G. Wuchterl, Heike Rauer, Suzanne Aigrain, Tristan Guillot, Thüringer Landessternwarte Tautenburg (TLS), Department of Brain and Behavioural Sciences, University of Pavia, Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), DLR Institute of Planetary Research, German Aerospace Center (DLR), Departamento de Matemàtica, PUC RIO, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ECLIPSE 2015, Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), 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), Institute of Planetary Research, German Aerospace Center, Rutherfordstrasse 2, 12489, Berlin, Germany, Türinger Landessternwarte Tautenburg, Dipartimento di Fisica, Università di Genova e Sezione INFN, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Astronomie (MPIA), Konkoly Observatory of the Hungarian Academy of Sciences, MTA CSFK, Budapest, Konkoly Thege Miklos ut, 15-17, Hungary, Department of Physics, Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK, Instituto de Astrofísica de Canarias (IAC), Etoile, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Haute résolution angulaire en astrophysique, Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF-Osservatorio Astrofisico di Torino Strada Osservatorio, 20 10025, Pino Torinese, TO, Italy, Observatoire astronomique de l'Universite de Geneve, 51 ch. des Maillettes, 1290, Versoix, Switzerland, Instituto Astronômico e Geofísico, Universidade de São Paulo (IAG), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Rheinisches Institut für Umweltforschung an der Universität zu Köln (RIU), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centro de Astrofisica da Universidade do Porto (CAUP), Laboratoire Univers et Théories (LUTH (UMR_8102)), Tel Aviv University (TAU), Max Planck Institut für Plasma Physik and Excellence Cluster, and Department of Earth and Planetary Sciences, Weizmann Institute of Science, 234 Herzl St., 76100, Rehovot, Israel
Subjects: Rotation period, Eclipses, Brown dwarf, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Brown dwarfs, Stars: rotation, Astronomy and Astrophysics, Space and Planetary Science, Planet, Hot Jupiter, Astrophysics::Solar and Stellar Astrophysics, 10. No inequality, Astrophysics::Galaxy Astrophysics, Commensurability (astronomy), Earth and Planetary Astrophysics (astro-ph.EP), Physics, VELOCIDADE, Astronomy, Orbital period, Exoplanet, Stars, 13. Climate action, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We report the detection of a rare transiting brown dwarf with a mass of 59 M_Jup and radius of 1.1 R_Jup around the metal-rich, [Fe/H] = +0.44, G9V star CoRoT-33. The orbit is eccentric (e = 0.07) with a period of 5.82 d. The companion, CoRoT-33b, is thus a new member in the so-called brown dwarf desert. The orbital period is within 3% to a 3:2 resonance with the rotational period of the star. CoRoT-33b may be an important test case for tidal evolution studies. The true frequency of brown dwarfs close to their host stars (P < 10 d) is estimated to be approximately 0.2% which is about six times smaller than the frequency of hot Jupiters in the same period range. We suspect that the frequency of brown dwarfs declines faster with decreasing period than that of giant planets., 13 pages, 8 figures, accepted for publication in A&A
Published: 2015
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36. Star formation in the Cepheus Flare region - II. A-type stars associated with IRAS sources

Author: Laszlo Szabados, J. Vinkó, and M. Kun
Subjects: Physics, Stars, T Tauri star, Space and Planetary Science, Be star, Star formation, K-type main-sequence star, Molecular cloud, Flare star, Astronomy, Astronomy and Astrophysics, Astrophysics, A-type main-sequence star
Abstract: ABSTRA C T In order to reveal the star-forming history of the molecular cloud complex we studied the intermediate mass stellar population in the Cepheus Flare region. (Paper I dealt with the distance and the young stellar object candidates of the region.) Correlating the IRAS Point Source Catalogue and Faint Source Catalogue positions with those of 1214 B8‐A8 and 1760 F0‐F5 type stars brighter than V < 13 mag and classified during an objective prism survey, we identified 19 stars showing far-infrared excess emission in the Cepheus Flare region. In addition to the 16 stars whose counterparts are given in the IRAS catalogues, we found three more stars with infrared excess not recognized before. In order to identify the young medium-mass stars associated with the Cepheus Flare molecular clouds we observed the optical spectra of the IR-excess stars, and using published optical photometry and the IRAS data we examined their spectral energy distributions (SEDs) and IRAS two-colour diagram. The observations resulted in the discovery of a new Herbig Ae/Be star, BD 16881118, coinciding with IRAS 2116916842. More evolved HAe/Be stars may be SAO 19953, BD 16781314 and BD 16981231, whose Ha lines showed weak emission components. Possible b Pictoris- or Vega-type stars may be HD 203854, HD 212826 and HD 216486, whereas the far-infrared fluxes at the positions of BD 17281018, HD 210806 and HD 217903 can be attributed to the heating of the interstellar environment. We used distances and radial velocities of the stars derived from the spectroscopy and published optical photometry as indicators of their relations to the clouds. Information on the environment of the observed stars deduced from the diffuse interstellar band at l 6613 is briefly discussed.
Published: 2002
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37. V473 Lyrae, a unique second-overtone Cepheid with two modulation cycles

Author: Laszlo Szabados and László Molnár
Subjects: Physics, Cepheid variable, Blazhko effect, Overtone, Phase (waves), Astronomy, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Radial velocity, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Modulation (music), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: V473 Lyrae is the only Galactic Cepheid with confirmed periodic amplitude and phase variations similar to the Blazhko effect observed in RR Lyrae stars. We collected all available photometric data and some radial velocity measurements to investigate the nature of the modulation. The comparison of the photometric and radial velocity amplitudes confirmed that the star pulsates in the second overtone. The extensive data set, spanning more than 40 years, allowed us to detect a secondary modulation cycle with a period of approximately 5300 days or 14.5 years. The secondary variations can be detected in the period of the primary modulation, as well. Phenomenologically, the light variations are analogous to the Blazhko effect. To find a physical link, we calculated linear hydrodynamic models to search for potential mode resonances that could drive the modulation and found two viable half-integer (n:2) and three n:4 resonances between the second overtone and other modes. If any of these resonances will be confirmed by non-linear models, it may confirm the mode resonance model, a common mechanism that can drive modulations both in RR Lyrae and Cepheid stars., Comment: 14 pages, 15 figures, accepted in MNRAS
Published: 2014

38. Toward an Orbit for the High‐Luminosity Cepheid T Monocerotis

Author: Glenn M. Wahlgren, Laszlo Szabados, Jozsef Vinko, Richard D. Robinson, Derck Massa, Nancy Remage Evans, and Kenneth G. Carpenter
Subjects: Physics, Orbital elements, Elliptic orbit, Cepheid variable, Astronomy, Binary number, Astronomy and Astrophysics, Orbital eccentricity, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Luminosity, Space and Planetary Science, Orbital motion, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Orbit (control theory), Astrophysics::Galaxy Astrophysics
Abstract: We have obtained new velocities of the long-period Cepheid T Mon from the ground and velocities of its hot companion with the Hubble Space Telescope (HST) and the International Ultraviolet Explorer (IUE). Although observations do not cover a full orbit, both the maximum and minimum orbital velocities have now been obtained. We present a preliminary orbit and discuss the uncertainties in the orbital parameters. The velocities for the companion appear to be inconsistent with binary orbital motion, and it is likely that the companion is itself a binary in a short-period orbit. The HST spectrum of the companion shows that it is a chemically peculiar star, probably magnetic. Because it is coupled with the more massive Cepheid, it must be very close to the zero-age main sequence. The well-determined mass function from the preliminary orbit implies that the inclination of the long-period system is close to 90°.
Published: 1999
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39. Spectroscopic survey of field Type II Cepheids

Author: Nancy Remage Evans, Laszlo Szabados, László L. Kiss, and Jozsef Vinko
Subjects: Physics, Stars, Wavelength, Brightness, Space and Planetary Science, Cepheid variable, Astronomy, Astronomy and Astrophysics, Astrophysics, Stellar classification, Spectral line, Galaxy rotation curve, Line (formation)
Abstract: A sample of relatively bright, short- and intermediate-period (P=1–10 d) Type II Cepheids in the Galactic field have been observed spectroscopically with an intermediate-resolution (λ/Δλ=11000) spectrograph. The wavelength region was 6500–6700 A, including the Hα line and some photospheric iron lines. The signal-to-noise ratio (S/N) was usually between 50 and 100, depending on weather conditions and the brightness of target stars. Radial velocities were determined by cross-correlating the Cepheid spectra with those of selected IAU velocity standard stars having F–G spectral types. The internal error of the velocity determination process was calculated to be about 1 km s−1. Hα emission and strong line splitting were observed in BL Her during the expansion phase, but no similar phenomenon was detected in any other stars in this programme, except for AU Peg which has an unusual Hα line showing a P Cygni-like profile. The velocity curve agrees well with recent CORAVEL measurements. The velocity gradients in Cepheid atmospheres are studied using the Hα minus metallic velocities. Similar data are collected from the literature. It seems that having large velocity differences (vHα−vmetal>40 km s−1) is a characteristic feature of the very short-period (P 10 d) Cepheids. Between these period regions the Cepheid atmospheres exhibit smaller velocity differences. Most of the Type II Cepheids observed in the present study fall into this latter category. There might be a tendency for classical Cepheids of intermediate period to have larger maximum velocity differences.
Published: 1998
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40. Multiplicity of Galactic Cepheids from long-baseline interferometry I. CHARA/MIRC detection of the companion of V1334 Cygni

Author: Judit Sturmann, Laszlo Szabados, Ettore Pedretti, Chris Farrington, Pierre Kervella, Fabien Baron, John D. Monnier, Antoine Mérand, Norm Vargas, Grzegorz Pietrzyński, T. ten Brummelaar, Laszlo Sturmann, Nils H. Turner, Gail H. Schaefer, Wolfgang Gieren, Harold A. McAlister, Alexandre Gallenne, Xiao Che, Stefan Kraus, and University of St Andrews. School of Physics and Astronomy
Subjects: Mass discrepancy, Cepheid variable, FOS: Physical sciences, Astrophysics, Type (model theory), Pulsation, 01 natural sciences, Speckle interferometry, Apparent magnitude, high angular resolution [Instrumentation], 0103 physical sciences, QB Astronomy, Spectroscopy, 010303 astronomy & astrophysics, Searching calibrators, Solar and Stellar Astrophysics (astro-ph.SR), QC, QB, Orbital elements, Physics, Distance scale, 010308 nuclear & particles physics, Classical cepheids, Astronomy and Astrophysics, Virtual observatory tool, Variable-star, Radial velocity, Stars, Interferometry, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Period-luminosity relation, variables: Cepheids [Stars], interferometric [Techniques], Surface brightness relations, close [Binaries]
Abstract: We aim at determining the masses of Cepheids in binary systems, as well as their geometric distances and the flux contribution of the companions. The combination of interferometry with spectroscopy will offer a unique and independent estimate of the Cepheid masses. Using long-baseline interferometry at visible and infrared wavelengths, it is possible to spatially resolve binary systems containing a Cepheid down to milliarcsecond separations. Based on the resulting visual orbit and radial velocities, we can then derive the fundamental parameters of these systems, particularly the masses of the components and the geometric distance. We therefore performed interferometric observations of the first-overtone mode Cepheid V1334 Cyg with the CHARA/MIRC combiner. We report the first detection of a Cepheid companion using long-baseline interferometry. We detect the signature of a companion orbiting V1334 Cyg at two epochs. We measure a flux ratio between the companion and the Cepheid f = 3.10+/-0.08%, giving an apparent magnitude mH = 8.47+/-0.15mag. The combination of interferometric and spectroscopic data have enabled the unique determination of the orbital elements: P = 1938.6+/-1.2 days, Tp = 2 443 616.1+/-7.3, a = 8.54+/-0.51mas, i = 124.7+/-1.8{\deg}, e = 0.190+/-0.013, {\omega} = 228.7+/-1.6{\deg}, and {\Omega} = 206.3+/-9.4{\deg}. We derive a minimal distance d ~ 691 pc, a minimum mass for both stars of 3.6 Msol, with a spectral type earlier than B5.5V for the companion star. Our measured flux ratio suggests that radial velocity detection of the companion using spectroscopy is within reach, and would provide an orbital parallax and model-free masses., Comment: Published in A&A
Published: 2013

41. Standard candles from the Gaia perspective

Author: Laszlo Szabados, Gisella Clementini, Laurent Eyer, Richard I. Anderson, L. Palaversa, D. W. Evans, Nami Mowlavi, Thomas Lebzelter, Silvio Leccia, Pierre Dubath, and Vincenzo Ripepi
Subjects: Physics, 010308 nuclear & particles physics, Cepheid variable, Cosmic distance ladder, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, 7. Clean energy, 01 natural sciences, Stars: distance, Stars: variables, Stars: binaries, Stars: statistics, Cosmology: distance scale, Space vehicles, Surveys, Catalogs, Stars, Perspective (geometry), Variable source, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Long period, 0103 physical sciences, ddc:520, Variable star, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: The ESA Gaia mission will bring a new era to the domain of standard candles. Progresses in this domain will be achieved thanks to unprecedented astrometric precision, whole-sky coverage and the combination of photometric, spectrophotometric and spectroscopic measurements. The fundamental outcome of the mission will be the Gaia catalogue produced by the Gaia Data Analysis and Processing Consortium (DPAC), which will contain a variable source classification and specific properties for stars of specific variability types. We review what will be produced for Cepheids, RR Lyrae, Long Period Variable stars and eclipsing binaries., Comment: 9 pages, 1 figure. Accepted for publication in Astrophysics and Space Science. Following a presentation at the conference The Fundamental Cosmic Distance Scale: State of the Art and the Gaia Perspective, Naples, May 2011
Published: 2012
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42. Quasi-Local Energy-Momentum and Angular Momentum in General Relativity

Author: Laszlo Szabados
Subjects: Physics, Quasi-local angular momentum, Physics and Astronomy (miscellaneous), General relativity, Energy–momentum relation, Review Article, Introduction to the mathematics of general relativity, lcsh:Atomic physics. Constitution and properties of matter, Specific relative angular momentum, lcsh:QC170-197, Classical mechanics, Total angular momentum quantum number, Angular momentum of light, Angular momentum coupling, Quasi-local mass, Angular momentum operator, Quasi-local energy-momentum
Abstract: The present status of the quasi-local mass, energy-momentum and angular-momentum constructions in general relativity is reviewed. First, the general ideas, concepts, and strategies, as well as the necessary tools to construct and analyze the quasi-local quantities, are recalled. Then, the various specific constructions and their properties (both successes and deficiencies are discussed. Finally, some of the (actual and potential) applications of the quasi-local concepts and specific constructions are briefly mentioned.This review is based on talks given at the Erwin Schrödinger Institute, Vienna in July 1997, at the Universität Tübingen in May 1998, and at the National Center for Theoretical Sciences in Hsinchu, Taiwan and at the National Central University, Chungli, Taiwan, in July 2000.
Published: 2009
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43. Observational studies of Cepheid amplitudes. I - Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes

Author: P. Klagyivik and Laszlo Szabados
Subjects: Physics, Cepheid variable, Overtone, Metallicity, FOS: Physical sciences, Astronomy and Astrophysics, Observable, Astrophysics, Radial velocity, Stars, Wavelength, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Aims: We attempt to revise the period-amplitude (P-A) relationship of Galactic Cepheids based on multi-colour photometric and radial velocity data. Reliable P-A graphs for Galactic Cepheids constructed for the U, B, V, R_C, and I_C photometric bands and pulsational radial velocity variations facilitate investigations of previously poorly studied interrelations between observable amplitudes. The effects of both binarity and metallicity on the observed amplitude, and the dichotomy between short- and long-period Cepheids can both be studied. Results: Large amplitude Cepheids with companions exhibit smaller photometric amplitudes on average than solitary ones, as expected, while s-Cepheids pulsate with an rbitrary (although small) amplitude. The ratio of the observed radial velocity to blue photometric amplitudes, A_V_RAD/A_B, is not as good an indicator of the ulsation mode as predicted theoretically. This may be caused by an incorrect mode assignment to a number of small amplitude Cepheids, which are not ecessarily first overtone pulsators. The dependence of the pulsation amplitudes on wavelength is used to identify duplicity of Cepheids. More than twenty stars previously classified as solitary Cepheids are now suspected to have a companion. The ratio of photometric amplitudes observed in various bands confirms the existence of a dichotomy among normal amplitude Cepheids. The limiting period separating short- and long-period Cepheids is 10.47 days. Conclusions: Interdependences of pulsational amplitudes, the period dependence of the amplitude parameters, and the dichotomy have to be taken into account as constraints in modelling the structure and pulsation of Cepheids. Studies of the P-L relationship must comply with the break at 10.47 instead of the currently used `convenient' value of 10 days., Comment: 14 pages, 9 Figures, 8 Tables, accepted for publication in A&A
Published: 2009
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44. L-Aminoguanidine Induces Imbalance of ROS/RNS Homeostasis and Polyamine Catabolism of Tomato Roots after Short-Term Salt Exposure

Author: Ágnes Szepesi, László Bakacsy, Attila Fehér, Henrietta Kovács, Péter Pálfi, Péter Poór, Réka Szőllősi, Orsolya Kinga Gondor, Tibor Janda, Gabriella Szalai, Christian Lindermayr, László Szabados, and Laura Zsigmond
Subjects: salt stress, polyamines, copper amine oxidases, nitric oxide, hydrogen sulfide, L-aminoguanidine, Therapeutics. Pharmacology, RM1-950
Abstract: Polyamine (PA) catabolism mediated by amine oxidases is an important process involved in fine-tuning PA homeostasis and related mechanisms during salt stress. The significance of these amine oxidases in short-term responses to salt stress is, however, not well understood. In the present study, the effects of L-aminoguanidine (AG) on tomato roots treated with short-term salt stress induced by NaCl were studied. AG is usually used as a copper amine oxidase (CuAO or DAO) inhibitor. In our study, other alterations of PA catabolism, such as reduced polyamine oxidase (PAO), were also observed in AG-treated plants. Salt stress led to an increase in the reactive oxygen and nitrogen species in tomato root apices, evidenced by in situ fluorescent staining and an increase in free PA levels. Such alterations were alleviated by AG treatment, showing the possible antioxidant effect of AG in tomato roots exposed to salt stress. PA catabolic enzyme activities decreased, while the imbalance of hydrogen peroxide (H2O2), nitric oxide (NO), and hydrogen sulfide (H2S) concentrations displayed a dependence on stress intensity. These changes suggest that AG-mediated inhibition could dramatically rearrange PA catabolism and related reactive species backgrounds, especially the NO-related mechanisms. More studies are, however, needed to decipher the precise mode of action of AG in plants exposed to stress treatments.
Published: 2023
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45. The long-period Galactic Cepheid RS Puppis - I. A geometric distance from its light echoes

Author: Laszlo Szabados, D. Bersier, Emanuela Pompei, Antoine Mérand, Pascal Fouqué, Pierre Kervella, Guy Perrin, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Center for High Angular Resolution Astronomy (CHARA), Georgia State University, University System of Georgia (USG)-University System of Georgia (USG), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Services communs OMP (UMS 831), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Astrophysics Research Institute [Liverpool] (ARI), Liverpool John Moores University (LJMU), European Southern Observatory (ESO), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: Cepheid variable, FOS: Physical sciences, Context (language use), Astrophysics, Star (graph theory), 01 natural sciences, Luminosity, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 0103 physical sciences, Stars: distances, 010303 astronomy & astrophysics, Physics, Nebula, 010308 nuclear & particles physics, extinction, Stars: variables: Cepheids, Astrophysics (astro-ph), Stars: individual: RS Pup, Astronomy and Astrophysics, Stars, Distance modulus, ISM: dust, Space and Planetary Science, ISM: reflection nebulae, Stars: circumstellar matter, Parallax
Abstract: Context: The bright southern Cepheid RS Pup is surrounded by a circumstellar nebula reflecting the light from the central star. The propagation of the light variations from the Cepheid inside the dusty nebula creates spectacular light echoes that can be observed up to large distances from the star itself. This phenomenon is currently unique in this class of stars. Aims: For this relatively distant star, the trigonometric parallax available from Hipparcos has a low accuracy. A careful observation of the light echoes has the potential to provide a very accurate, geometric distance to RS Pup. Methods: We obtained a series of CCD images of RS Pup with the NTT/EMMI instrument, covering the variation period of the star (P=41.4d). This allowed us to track the progression of the light wavefronts over the nebular features surrounding the star. We measured precisely the phase lag of the photometric variation in several regions of the circumstellar nebula. Results: From our phase lag measurements, we derived a geometric distance of 1992 +/- 28 pc to RS Pup. This distance is affected by a total uncertainty of 1.4%, and corresponds to a parallax of pi = 0.502 +/- 0.007 mas and a distance modulus of mu = 11.50 +/- 0.03. Conclusions: The geometric distance we derived is by far the most accurate to a Cepheid, and among the most accurate to any star. RS Pup appears both as somewhat neglected and particularly promising to investigate the mass-loss history of Cepheids. Thanks to its highly accurate distance, it is also bound to become an important luminosity fiducial for the long period part of the period-luminosity diagram., 14 pages in electronic form. Astronomy and Astrophysics (2007) in press
Published: 2007
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46. Pulsation and orbit of AU Pegasi

Author: Laszlo Szabados, Jozsef Vinko, M. Jurkovic, and B. Csák
Subjects: Physics, Cepheid variable, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Orbital period, symbols.namesake, Orbit, Space and Planetary Science, Fourier analysis, Observatory, symbols, Astrophysics::Solar and Stellar Astrophysics, Binary system, Astrophysics::Galaxy Astrophysics
Abstract: AU Pegasi is a pulsating star in a spectroscopic binary system with an orbital period of 53.26 days. Between 1960 and 1990 an extremely rapid period increase was observed in the value of the pulsation period, but in the last 15 years the observation show that the period set in 2.411 days. Fourier analysis of photometric data obtained during the ASAS project and those taken at the Piszkesteto Mountain Station of the Konkoly Observatory during 1994-2005 indicate that AU Pegasi is pulsating in two modes simultaneously, and the ratio of the frequencies of the two modes is 0.706, a value common for double-mode classical Cepheids. A careful analysis of other photometric observations obtained during the era of the strong period increase also revealed existence of a second mode. This may suggest that this star is not a Type II Cepheid, despite its galactic position., 4 pages, 10 figures
Published: 2007

47. The anomalous Cepheid XZ Ceti

Author: Laszlo Szabados, László L. Kiss, and Aliz Derekas
Subjects: Physics, Cepheid variable, Astrophysics (astro-ph), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Phase curve, Light curve, Galaxy, Radial velocity, Amplitude, Space and Planetary Science, Globular cluster, Astrophysics::Solar and Stellar Astrophysics, Variable star, Astrophysics::Galaxy Astrophysics
Abstract: XZ Ceti is the only known anomalous Cepheid in the Galactic field. Being the nearest and brightest such variable star, a detailed study of XZ Ceti may shed light on the behaviour of anomalous Cepheids whose representatives have been mostly detected in external galaxies. CCD photometric and radial velocity observations have been obtained. The actual period and amplitude of pulsation were determined by Fourier analysis. The long time scale behaviour of the pulsation period was studied by the method of the O-C diagram using the archival Harvard photographic plates and published photometric data. XZ Ceti differs from the ordinary classical Cepheids in several respects. Its most peculiar feature is cycle-to-cycle variability of the light curve. The radial velocity phase curve is not stable either. The pulsation period is subjected to strong changes on various time scales including a very short one. The ratio of amplitudes determined from the photometric and radial velocity observations indicates that this Cepheid performs an overtone pulsation, in accord with the other known anomalous Cepheid in our Galaxy, BL Boo (V19 in the globular cluster NGC 5466). Continued observations are necessary to study the deviations from regularity, to determine their time scale, as well as to confirm binarity of XZ Ceti and to study its role in the observed peculiar behaviour., 7 pages, 4 figures. accepted for Astron. Astrophys
Published: 2006

48. The Poincaré Structure and the Centre-of-Mass of Asymptotically Flat Spacetimes

Author: Laszlo Szabados
Subjects: Physics, General Relativity and Quantum Cosmology, symbols.namesake, Angular momentum, Classical mechanics, Spacetime, Total angular momentum quantum number, General relativity, Lorentz transformation, Minkowski space, symbols, Hamiltonian (quantum mechanics), Conserved quantity
Abstract: The asymptotic symmetries and the conserved quantities of asymp- totically flat spacetimes are investigated by extending the canonical analysis of vacuum general relativity of Beig and ´ O Murchadha. It is shown that the algebra of asymptotic Killing symmetries, defined with respect to a given foliation of the spacetime, depends on the fall-off rate of the metric. It is only the Lorentz Lie algebra for slow fall-off, but it is the Poincarea lgebra for 1 /r or faster fall-off. The energy-momentum and (relativistic) angular momentum are defined by the value of the Beig- ´ O Murchadha Hamiltonian with lapse and shift corresponding to asymptotic Killing vectors. While this energy-momentum and spatial angular momentum reproduce the familiar ADM energy-momentum and Regge-Teitelboim angular momentum, respectively, the centre-of-mass deviates from that of Beig and ´ O Murchadha. The new centre-of-mass is conserved, and, together with the spatial angular momentum, form an anti-symmetric Lorentz tensor which transforms just in the correct way under asymptotic Poincare transformations of the asymptotically Cartesian coordinate system.
Published: 2006
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49. Sustained Division of Sugarbeet (Beta vulgaris) Protoplasts : Stimulating Effect of Conditioned Media

Author: László, Szabados, Carina, Gaggero, Potrykus, I., editor, Harms, C. T., editor, Hinnen, A., editor, Hütter, R., editor, King, P. J., editor, and Shillito, R. D., editor
Published: 1983
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50. The long-period Galactic Cepheid RS Puppis. III. A geometric distance from HST polarimetric imaging of its light echoes

Author: Laszlo Szabados, Pascal Fouqué, Richard I. Anderson, D. Bersier, Pierre Kervella, Misty Cracraft, J. Breitfelder, William B. Sparks, Alexandre Gallenne, Antoine Mérand, and Howard E. Bond
Subjects: Physics, Brightness, Nebula, 010308 nuclear & particles physics, Reflection nebula, Cepheid variable, Linear polarization, Milky Way, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, symbols.namesake, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Rayleigh scattering, Parallax, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: As one of the most luminous Cepheids in the Milky Way, the 41.5-day RS Puppis is an analog of the long-period Cepheids used to measure extragalactic distances. An accurate distance to this star would therefore help anchor the zero-point of the bright end of the period-luminosity relation. But, at a distance of about 2 kpc, RS Pup is too far away for measuring a direct trigonometric parallax with a precision of a few percent with existing instrumentation. RS Pup is unique in being surrounded by a reflection nebula, whose brightness varies as pulses of light from the Cepheid propagate outwards. We present new polarimetric imaging of the nebula obtained with HST/ACS. The derived map of the degree of linear polarization pL allows us to reconstruct the three-dimensional structure of the dust distribution. To retrieve the scattering angle from the pL value, we consider two different polarization models, one based on a Milky Way dust mixture and one assuming Rayleigh scattering. Considering the derived dust distribution in the nebula, we adjust a model of the phase lag of the photometric variations over selected nebular features to retrieve the distance of RS Pup. We obtain a distance of 1910 +/- 80 pc (4.2%), corresponding to a parallax of 0.524 +/- 0.022 mas. The agreement between the two polarization models we considered is good, but the final uncertainty is dominated by systematics in the adopted model parameters. The distance we obtain is consistent with existing measurements from the literature, but light echoes provide a distance estimate that is not subject to the same systematic uncertainties as other estimators (e.g. the Baade-Wesselink technique). RS Pup therefore provides an important fiducial for the calibration of systematic uncertainties of the long-period Cepheid distance scale., Comment: 14 pages, 14 figures, accepted for publication in Astronomy & Astrophysics
Published: 2014
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