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1. RR Lyrae Stars as Seen by the Kepler Space Telescope

Author: Emese Plachy and Róbert Szabó
Subjects: RR Lyrae stars, Kepler spacecraft, Blazhko effect, pulsating variable stars, horizontal-branch stars, pulsation, Astronomy, QB1-991, Geophysics. Cosmic physics, QC801-809
Abstract: The unprecedented photometric precision along with the quasi-continuous sampling provided by the Kepler space telescope revealed new and unpredicted phenomena that reformed and invigorated RR Lyrae star research. The discovery of period doubling and the wealth of low-amplitude modes enlightened the complexity of the pulsation behavior and guided us toward nonlinear and nonradial studies. Searching and providing theoretical explanation for these newly found phenomena became a central question, as well as understanding their connection to the oldest enigma of RR Lyrae stars, the Blazhko effect. We attempt to summarize the highest impact RR Lyrae results based on or inspired by the data of the Kepler space telescope both from the nominal and from the K2 missions. Besides the three most intriguing topics, the period doubling, the low-amplitude modes, and the Blazhko effect, we also discuss the challenges of Kepler photometry that played a crucial role in the results. The secrets of these amazing variables, uncovered by Kepler, keep the theoretical, ground-based, and space-based research inspired in the post-Kepler era, since light variation of RR Lyrae stars is still not completely understood.
Published: 2021
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2. Type II and anomalous Cepheids in the Kepler K2 mission

Author: Monika I Jurkovic, Emese Plachy, László Molnár, Martin A T Groenewegen, Attila Bódi, Pawel Moskalik, and Róbert Szabó
Subjects: Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present the results of the analysis of Type II and anomalous Cepheids using the data from the Kepler K2 mission. The precise light curves of these pulsating variable stars are the key to study the details of their pulsation, such as the period-doubling effect or the presence of additional modes. We applied the Automated Extended Aperture Photometry (autoEAP) to obtain the light curves of the targeted variable stars which were observed. The light curves were Fourier analyzed. We investigated twelve stars observed by the K2 mission, seven Type II and five anomalous Cepheids. Among the Type II Cepheids EPIC 210622262 shows period-doubling, and four stars have modulation present in their light curves which are different from the period-doubling effect. We calculated the high-order Fourier parameters for the short-period Cepheids. We also determined physical parameters by fitting model atmospheres to the spectral energy distributions. The determined distances using the parallaxes measured by the Gaia space telescope have limited precision below 16 mag for these types of pulsating stars, regardless if the inverse method is used or the statistical method to calculate the distances. The BaSTI evolutionary models were compared to the luminosities and effective temperatures. Most of the Type II Cepheids are modeled with low metallicity models, but for a few of them solar-like metallicity ([Fe/H]=0.06) model is required. The anomalous Cepheids are compared to low-metallicity single stellar models. We do not see signs of binarity among our sample stars., 21 pages, 13 figures, accepted for publication in MNRAS
Published: 2022

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. Automated Extended Aperture Photometry of K2 variable stars

Author: Attila Bódi, Pál Szabó, Emese Plachy, László Molnár, and Róbert Szabó
Subjects: Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Proper photometric data are challenging to obtain in the K2 mission of the Kepler space telescope due to strong systematics caused by the two-wheel-mode operation. It is especially true for variable stars wherein physical phenomena occur on timescales similar to the instrumental signals. We originally developed a method with the aim to extend the photometric aperture to be able to compensate the motion of the telescope which we named Extended Aperture Photometry (EAP). Here we present the outline of the automatized version of the EAP method, an open-source pipeline called autoEAP. We compare the light curve products to other photometric solutions for examples chosen from high-amplitude variable stars. Besides the photometry, we developed a new detrending method, which is based on phase dispersion minimization and is able to eliminate long-term instrumental signals for periodic variable stars., Comment: 15 pages, 12 figures. Accepted for publication in PASP. Code available on GitHub: https://github.com/konkolyseismolab/autoeap. Light curve data available: https://konkoly.hu/KIK/data_en.html
Published: 2021
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5. 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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6. 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

7. HD 344787: a true Polaris analogue?

Author: G. De Somma, Felice Cusano, V. Ripepi, S. Mancino, Vincenzo Testa, Giovanni Catanzaro, Marcella Marconi, Roberto Molinaro, László Molnár, Ilaria Musella, S. Leccia, G. Clementini, and Emese Plachy
Subjects: 010309 optics, Physics, Polaris, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Classical Cepheids (DCEPs) are the most important primary indicators for the extragalactic distance scale, but they are also important objects per se, allowing us to put constraints on the physics of intermediate-mass stars and the pulsation theories. We have investigated the peculiar DCEP HD 344787, which is known to exhibit the fastest positive period change among DCEPs along with a quenching amplitude of the light variation. We have used high-resolution spectra obtained with HARPS-N@TNG for HD 344787 and the more famous Polaris DCEP, to infer their detailed chemical abundances. Results from the analysis of new time-series photometry of HD 344787 obtained by the TESS satellite are also reported. The double mode nature of HD344787 pulsation is confirmed by analysis of the TESS light curve, although with rather tiny amplitudes of a few tens of millimag. This is an indication that HD344787 is on the verge of quenching the pulsation. Analysis of the HARPS-N@TNG spectra reveals an almost solar abundance and no depletion of carbon and oxygen. Hence, the star appears to have not gone through the first dredge-up. Similar results are obtained for Polaris. Polaris and HD344787 are confirmed to be both most likely at their first crossing of the instability strip (IS). The two stars are likely at the opposite borders of the IS for first overtone DCEPs with metal abundance Z=0.008. A comparison with other DCEPs which are also thought to be at their first crossing allows us to speculate that the differences we see in the Hertzsprung-Russell diagram might be due to differences in the properties of the DCEP progenitors during the main sequence phase., Comment: 9 pages, 6 figures, Astronomy & Astrophysics in press. Version corrected by Language Editor
Published: 2021

8. 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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9. RR Lyrae stars as seen by the Kepler space telescope

Author: Emese Plachy and Róbert Szabó
Subjects: lcsh:Astronomy, Blazhko effect, FOS: Physical sciences, RR Lyrae variable, 01 natural sciences, Kepler, Asteroseismology, Photometry (optics), lcsh:QB1-991, Spitzer Space Telescope, 0103 physical sciences, RR Lyrae stars, Variation (astronomy), 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Physics, horizontal-branch stars, 010308 nuclear & particles physics, lcsh:QC801-809, Astronomy, Astronomy and Astrophysics, Horizontal branch, Kepler spacecraft, lcsh:Geophysics. Cosmic physics, Astrophysics - Solar and Stellar Astrophysics, pulsation, pulsating variable stars, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The unprecedented photometric precision along with the quasi-continuous sampling provided by the Kepler space telescope revealed new and unpredicted phenomena that reformed and invigorated RR Lyrae star research. The discovery of period doubling and the wealth of low-amplitude modes enlightened the complexity of the pulsation behavior and guided us towards nonlinear and nonradial studies. Searching and providing theoretical explanation for these newly found phenomena became a central question, as well as understanding their connection to the oldest enigma of RR Lyrae stars, the Blazhko effect. We attempt to summarize the highest impact RR Lyrae results based on or inspired by the data of the Kepler space telescope both from the nominal and the K2 missions. Besides the three most intriguing topics, the period doubling, the low-amplitude modes, and the Blazhko effect, we also discuss the challenges of Kepler photometry that played a crucial role in the results. The secrets of these amazing variables, uncovered by Kepler, keep the theoretical, ground-based and space-based research inspired in the post-Kepler era, since light variation of RR Lyrae stars is still not completely understood., 25 pages, 9 figures, review article, accepted in Frontiers in Astronomy and Space Sciences
Published: 2020

10. X-Ray Observations of the Peculiar Cepheid V473 Lyr Identify A Low-mass Companion

Author: László Molnár, Edward F. Guinan, László Szabados, Róbert Szabó, Gilbert Burki, Vinay L. Kashyap, Hilding R. Neilson, Scott J. Wolk, H. Moritz Günther, Jeremy J. Drake, Nancy Remage Evans, Massimo Marengo, Peter Somogyi, Ignazio Pillitteri, Sofia P. Moschou, Lynn D. Matthews, Tamás Tordai, Pierre Kervella, Emese Plachy, Scott G. Engle, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Cepheid variable, Astrophysics::High Energy Astrophysical Phenomena, X-ray, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 10. No inequality, Low Mass, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS
Abstract: V473 Lyr is a classical Cepheid which is unique in having substantial amplitude variations with a period of approximately 3.3 years, thought to be similar to the Blazhko variations in RR Lyrae stars. We obtained an {\it XMM-Newton} observation of this star to followup a previous detection in X-rays. Rather than the X-ray burst and rapid decline near maximum radius seen in $\delta$ Cephei itself, the X-ray flux in V473 Lyr remained constant for a third of the pulsation cycle covered by the observation. Thus the X-rays are most probably not produced by the changes around the pulsation cycle. The X-ray spectrum is soft (kT = 0.6 keV), with X-ray properties which are consistent with a young low mass companion. Previously there was no evidence of a companion in radial velocities or in {\it Gaia} and {\it Hipparcos} proper motions. While this rules out companions which are very close or very distant, a binary companion at a separation between 30 and 300 AU is possible. This is an example of an X-ray observation revealing evidence of a low mass companion, which is important in completing the mass ratio statistics of binary Cepheids. Furthermore, the detection of a young X-ray bright companion is a further indication that the Cepheid (primary) is a Population I star, even though its pulsation behavior differs from other classical Cepheids., Comment: Accepted by AJ
Published: 2020
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11. 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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12. Wandering near the red edge: photometric observations of three cool ZZ Ceti stars

Author: D. I. Jenei, M. Chavez-Dagostino, M. Paparó, Zs. Bognár, E. Verebélyi, H. Ollé, Emese Plachy, Péter Pápics, Ádám Sódor, Michael H. Montgomery, Cs. Kalup, Emanuele Bertone, Á. Győrffy, and László Molnár
Subjects: oscillations [stars], Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), FOS: Physical sciences, Red edge, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, law.invention, photometric [techniques], WHOLE EARTH TELESCOPE, Telescope, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, PULSATING WHITE-DWARF, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), white dwarfs, Physics, Science & Technology, 010308 nuclear & particles physics, White dwarf, Astronomy and Astrophysics, individual: HS 0733+4119, GD 154, Ross 808 [stars], Stars, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Physical Sciences, Instability strip
Abstract: We summarize our findings on three cool ZZ Ceti type pulsating white dwarfs. We determined eight independent modes in HS 0733+4119, of which seven are new findings. For GD 154, we detected two new eigenmodes, and the recurrence of the pulsational behaviour first observed in 1977. We discuss that GD 154 does not only vary its pulsations between a multiperiodic and a quasi-monoperiodic phase, but there are also differences between the relative amplitudes of the near-subharmonics observed in the latter phase. In the complex pulsator, Ross 808, we compared the pre- and post Whole Earth Telescope campaign measurements, and determined two new frequencies besides the ones observed during the campaign. Studying these stars can contribute to better understanding of pulsations close to the empirical ZZ Ceti red edge. All three targets are in that regime of the ZZ Ceti instability strip where short-term amplitude variations or even outbursts are likely to occur, which are not well-understood theoretically., 15 pages, 13 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
Published: 2018
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13. The composition of Barium stars and the s-process in AGB stars

Author: B. Cseh, Maria Lugaro, Sergio Cristallo, Denise B. de Castro, Valentina D'Orazi, C. B. Pereira, László Molnár, Marco Pignatari, Róbert Szabó, Amanda I. Karakas, and Emese Plachy
Subjects: Physics, Nuclear reaction, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, Astronomy and Astrophysics, Barium, Astrophysics, Composition (combinatorics), 01 natural sciences, Stars, chemistry, Space and Planetary Science, Nucleosynthesis, 0103 physical sciences, s-process, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Using abundances from the available largest, homogeneous sample of high resolution Barium (Ba) star spectra we calculated the ratios of different hs-like to ls-like elemental ratios and compared to different AGB nucleosynthesis models. The Ba star data show an incontestable increase of the hs-type/ls-type element ratio (for example, [Ce/Y]) with decreasing metallicity. This trend in the Ba star observations is predicted by low mass, non-rotating AGB models where 13C is the main neutron source and is in agreement with Kepler asteroseismology observations.
Published: 2018
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14. Do meteoritic silicon carbide grains originate from asymptotic giant branch stars of super-solar metallicity?

Author: Mária K. Pető, Maria Lugaro, Amanda I. Karakas, and Emese Plachy
Subjects: Physics, Opacity, 010308 nuclear & particles physics, Metallicity, FOS: Physical sciences, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Galaxy, Stars, Stellar nucleosynthesis, Astrophysics - Solar and Stellar Astrophysics, Geochemistry and Petrology, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, Neutron, Astrophysics::Earth and Planetary Astrophysics, s-process, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: We compare literature data for the isotopic ratios of Zr, Sr, and Ba from analysis of single meteoritic stardust silicon carbide (SiC) grains to new predictions for the slow neutron-capture process (the s process) in metal-rich asymptotic giant branch (AGB) stars. The models have initial metallicities Z = 0.014 (solar) and Z = 0.03 (twice-solar) and initial masses 2 - 4.5 Msun, selected such as the condition C/O>1 for the formation of SiC is achieved. Because of the higher Fe abundance, the twice-solar metallicity models result in a lower number of total free neutrons released by the 13C({\alpha},n)16O neutron source. Furthermore, the highest-mass (4 - 4.5 Msun) AGB stars of twice-solar metallicity present a milder activation of the 22Ne({\alpha},n)25Mg neutron source than their solar metallicity counterparts, due to cooler temperatures resulting from the effect of higher opacities. They also have a lower amount of the 13C neutron source than the lower-mass models, following their smaller He-rich region. The combination of these different effects allows our AGB models of twice-solar metallicity to provide a match to the SiC data without the need to consider large variations in the features of the 13C neutron source nor neutron-capture processes different from the s process. This raises the question if the AGB parent stars of meteoritic SiC grains were in fact on average of twice-solar metallicity. The heavier-than-solar Si and Ti isotopic ratios in the same grains are in qualitative agreement with an origin in stars of super-solar metallicity because of the chemical evolution of the Galaxy. Further, the SiC dust mass ejected from C-rich AGB stars is predicted to significantly increase with increasing the metallicity., Comment: 40 pages, 7 figures, 1 table. Accepted for publication on Geochimica Cosmochimica Acta
Published: 2018
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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. On Barium Stars and the s-Process in AGB Stars

Author: László Molnár, Denise B. de Castro, Valentina D'Orazi, C. B. Pereira, B. Cseh, Maria Lugaro, Róbert Szabó, Amanda I. Karakas, and Emese Plachy
Subjects: Physics, Metallicity, chemistry.chemical_element, Barium, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Star (graph theory), Stars, chemistry, Homogeneous, Astrophysics::Solar and Stellar Astrophysics, Neutron source, Low Mass, s-process, Astrophysics::Galaxy Astrophysics
Abstract: A new large set of homogeneous high resolution spectra of Barium (Ba) stars makes it now possible to compare the observational data from only one study with different AGB models. The Ba star data show an incontestable increase of the hs-type/ls-type element ratio (for example, [Ce/Y]) with decreasing metallicity. This trend in the Ba star observations is predicted by low mass, non-rotating AGB models where $^{13}$C is the main neutron source.
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. Solar System Objects Observed with TESS—First Data Release: Bright Main-belt and Trojan Asteroids from the Southern Survey

Author: László Molnár, László L. Kiss, Csaba Kiss, R. Szakats, Gábor Marton, Emese Plachy, András Pál, R. Szabó, Krisztián Sárneczky, Csilla Kalup, Gyula M. Szabó, Z. Bognár, and Attila Bódi
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, Solar System, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Space and Planetary Science, Trojan, Physics::Space Physics, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Data release, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: Compared with previous space-borne surveys, the Transiting Exoplanet Survey Satellite (TESS) provides a unique and new approach to observe Solar System objects. While its primary mission avoids the vicinity of the ecliptic plane by approximately six degrees, the scale height of the Solar System debris disk is large enough to place various small body populations in the field-of-view. In this paper we present the first data release of photometric analysis of TESS observations of small Solar System Bodies, focusing on the bright end of the observed main-belt asteroid and Jovian Trojan populations. This data release, named TSSYS-DR1, contains 9912 light curves obtained and extracted in a homogeneous manner, and triples the number of bodies with unambiguous fundamental rotation characteristics, namely where accurate periods and amplitudes are both reported. Our catalogue clearly shows that the number of bodies with long rotation periods are definitely underestimated by all previous ground-based surveys, by at least an order of magnitude., ApJS, in press. Data are available from https://archive.konkoly.hu/pub/tssys/dr1/ (6.36G, in total)
Published: 2020
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19. Gaia Data Release 2: Validation of the classification of RR Lyrae and Cepheid variables with the Kepler and K2 missions

Author: Á. L. Juhász, Lorenzo Rimoldini, Emese Plachy, and László Molnár
Subjects: Physics, Cepheid variable, Astronomy and Astrophysics, Context (language use), Astrophysics, RR Lyrae variable, Light curve, 01 natural sciences, Photometry (astronomy), Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Bulge, 0103 physical sciences, Variable star, 010306 general physics, 010303 astronomy & astrophysics
Abstract: The second data release of the Gaia mission includes an advance catalog of variable stars. The classification of these stars are based on sparse photometry from the first 22 months of the mission. We set out to investigate the purity and completeness of the all-sky Gaia classification results with the help of the continuous light curves of the observed targets from the Kepler and K2 missions, focusing specifically on RR Lyrae and Cepheid pulsators, outside the Galactic Bulge region. We crossmatched the Gaia identifications with the observations collected by the Kepler space telescope. We inspected the light curves visually, then calculated the relative Fourier coefficients and period ratios for the single- and double-mode K2 RR Lyrae stars to further classify them. We identified 1443 and 41 stars classified as RR Lyrae or Cepheid variables in Gaia DR2 in the targeted observations of the two missions and 263 more RR Lyre targets in the Full-Frame Images (FFI) of the original mission. We provide the crossmatch of these sources. We conclude that the RR Lyrae catalog has a completeness between 70-78%, and provide a purity estimate between 92-98% (targeted observations) with lower limits of 75% (FFI stars) and 51% (K2 worst-case scenario). The low number of Cepheids prevents us from drawing detailed conclusions but the purity of the DR2 sample is estimated to be around 66%., Comment: 15 pages, 12 figures, 10 tables, accepted into the Gaia DR2 Special Issue in A&A. V1: submitted version, v2: accepted version. Lists available at http://konkoly.hu/~lmolnar/gaiakepler_datafiles_R1.zip
Published: 2018

20. Gaia Data Release 2: Summary of the variability processing & analysis results

Author: László Molnár, I. Pagano, László Szabados, G. Busso, Richard I. Anderson, Shay Zucker, Marcella Marconi, P. Koubsky, L. M. Sarro, Lorenzo Rimoldini, Andrej Prsa, Viktor Votruba, Leanne P. Guy, M. Riello, A. Kochoska, Vincenzo Ripepi, Gisella Clementini, M. López, Tsevi Mazeh, S. Regibo, M. Grenon, F. Glass, G. Marschalkó, S. Messina, J. De Ridder, K. Nienartowicz, L. Eyer, J. Charnas, Tatiana Muraveva, André Moitinho, S. Morgenthaler, L. Palaversa, D. W. Evans, O. Marchal, Marc Audard, Sergi Blanco-Cuaresma, Ilaria Musella, Conny Aerts, Michał Pawlak, A. Garofalo, Á. L. Juhász, D. Ordonez, Isabelle Lecoeur-Taïbi, Antonino F. Lanza, E. Distefano, B. Holl, A. C. Lanzafame, Maria Süveges, G. Jevardat de Fombelle, C. Ordénovic, J. Cuypers, T. Lebzelter, Nami Mowlavi, Emese Plachy, Francois Mignard, Maroussia Roelens, F. De Angeli, F. Barblan, Roberto Molinaro, Silvio Leccia, D. Lorenz, A. Panahi, E. Szegedi-Elek, Heckscher-Klinikum, ISDC Data Centre for Astrophysics, University of Geneva [Switzerland], Galaxies, Etoiles, Physique, Instrumentation (GEPI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Instituut voor Sterrenkunde [Leuven], Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Aberystwyth University, Laboratory of the Institute for Fiscal Studies (IFS), Institute for Fiscal Studies, INAF - Osservatorio Astrofisico di Catania (OACT), Istituto Nazionale di Astrofisica (INAF), Département Réseaux, Information, Multimédia (RIM-ENSMSE), École des Mines de Saint-Étienne (Mines Saint-Étienne MSE), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre G2I, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Laboratoire d'études dynamiques et structurales de la sélectivité (LEDSS), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Astrofisica (Istituto Nazionale di Astrofisica), Istituto Nazionale di Fisica Nucleare (INFN), INAF - Osservatorio Astronomico di Capodimonte (OAC), Universidad Nacional de Educación a Distancia (UNED), Case Western Reserve University [Cleveland], Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Royal Observatory of Belgium [Brussels] (ROB), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), NSF Center for EUV Science and Technology, NSF, School of Physics and Astronomy [Tel Aviv], Tel Aviv University [Tel Aviv], 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), SIM/IDL Faculdade de Ciências da Universidade de Lisboa (FCUL), University of Lisboa, Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Geneva Observatory, Holl, B., Audard, M., Nienartowicz, K., Jevardat De Fombelle, G., Marchal, O., Mowlavi, N., Clementini, G., De Ridder, J., Evans, D.W., Guy, L.P., Lanzafame, A.C., Lebzelter, T., Rimoldini, L., Roelens, M., Zucker, S., Distefano, E., Garofalo, A., Lecoeur-Taïbi, I., Lopez, M., Molinaro, R., Muraveva, T., Panahi, A., Regibo, S., Ripepi, V., Sarro, L.M., Aerts, C., Anderson, R.I., Charnas, J., Barblan, F., Blanco-Cuaresma, S., Busso, G., Cuypers, J., De Angeli, F., Glass, F., Grenon, M., Juhász, Ã .L., Kochoska, A., Koubsky, P., Lanza, A.F., Leccia, S., Lorenz, D., Marconi, M., Marschalkó, G., Mazeh, T., Messina, S., Mignard, F., Moitinho, A., Molnár, L., Morgenthaler, S., Musella, I., Ordenovic, C., Ordóñez, D., Pagano, I., Palaversa, L., Pawlak, M., Plachy, E., Prša, A., Riello, M., Söveges, M., Szabados, L., Szegedi-Elek, E., Votruba, V., and Eyer, L.
Subjects: Catalogs, Galaxy: stellar content, Stars: general, Stars: oscillations, Stars: solar-Type, Stars: variables: general, Astronomy and Astrophysics, Space and Planetary Science, Cepheid variable, Astronomy, media_common.quotation_subject, FOS: Physical sciences, Astrophysics, RR Lyrae variable, 01 natural sciences, Photometry (optics), 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Stars: oscillation, media_common, [PHYS]Physics [physics], Physics, 010308 nuclear & particles physics, Probabilistic logic, Astronomy and Astrophysic, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Sky, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, stars: general, stars: oscillations, stars: solar-type, stars: variables: general, catalogs, Catalog, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Completeness (statistics), Astrophysics - Instrumentation and Methods for Astrophysics, Data release
Abstract: The Gaia Data Release 2 (DR2): we summarise the processing and results of the identification of variable source candidates of RR Lyrae stars, Cepheids, long period variables (LPVs), rotation modulation (BY Dra-type) stars, delta Scuti & SX Phoenicis stars, and short-timescale variables. In this release we aim to provide useful but not necessarily complete samples of candidates. The processed Gaia data consist of the G, BP, and RP photometry during the first 22 months of operations as well as positions and parallaxes. Various methods from classical statistics, data mining and time series analysis were applied and tailored to the specific properties of Gaia data, as well as various visualisation tools. The DR2 variability release contains: 228'904 RR Lyrae stars, 11'438 Cepheids, 151'761 LPVs, 147'535 stars with rotation modulation, 8'882 delta Scuti & SX Phoenicis stars, and 3'018 short-timescale variables. These results are distributed over a classification and various Specific Object Studies (SOS) tables in the Gaia archive, along with the three-band time series and associated statistics for the underlying 550'737 unique sources. We estimate that about half of them are newly identified variables. The variability type completeness varies strongly as function of sky position due to the non-uniform sky coverage and intermediate calibration level of this data. The probabilistic and automated nature of this work implies certain completeness and contamination rates which are quantified so that users can anticipate their effects. This means that even well-known variable sources can be missed or misidentified in the published data. The DR2 variability release only represents a small subset of the processed data. Future releases will include more variable sources and data products; however, DR2 shows the (already) very high quality of the data and great promise for variability studies., 21 pages, 10 figures, 5 tables, accepted by Astronomy & Astrophysics, added several language corrections, and expanded Gaia archive query examples
Published: 2018
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21. Innovative or sustainable? Future of the IBVS

Author: Mihály Váradi, András Holl, László Molnár, Emese Plachy, Evelin Bányai, and László Szabados
Subjects: Open source, Software, business.industry, Process (engineering), Physics, QC1-999, 05 social sciences, 0509 other social sciences, 050904 information & library sciences, business, Data science, GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries), Term (time)
Abstract: Long-term archiving of scientific information is a well known challenge. We discuss the issue of preservation for journals and their enhanced versions. We use the Information Bulletin on Variable Stars as an example. This express journal, created to satisfy the need of researchers for rapid dissemination of discoveries and results has been developed to become an enhanced journal, with several data journal features. However, the original software developed for the enhanced web version of the journal is not sustainable for the long term. We discuss the possibilities for moving the journal to a standard open source platform, and the trade-offs of the process. Long-term preservation of content, including data, is addressed as well.
Published: 2018

22. Chaotic dynamics in the pulsation of DF Cygni, as observed by Kepler

Author: Emese Plachy, A. Bódi, and Zoltán Kolláth
Subjects: Physics, Lyapunov function, Astrophysics::High Energy Astrophysical Phenomena, Chaotic, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Star (graph theory), 01 natural sciences, 010305 fluids & plasmas, symbols.namesake, Nonlinear system, Astrophysics - Solar and Stellar Astrophysics, Spitzer Space Telescope, Space and Planetary Science, 0103 physical sciences, symbols, Astrophysics::Solar and Stellar Astrophysics, Supergiant, Variable star, Variation (astronomy), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Pulsations of RV Tauri-type variable stars can be governed by chaotic dynamics. However, observational evidence for this happening is usually hard to come by. Here we use the continuous, 4-year-long observations of the Kepler space telescope to search for the signs of chaos in the RVb-type pulsating supergiant, DF Cygni. We use the Global Flow Reconstruction method to estimate the quantitative properties of the dynamics driving the pulsations of the star. The secondary, long-term light variation, i.e., the RVb phenomenon was removed in the analysis with the Empirical Mode Decomposition method. Our analysis revealed that the pulsation of DF Cyg could be described as a chaotic signal with a Lyapunov dimension of ~2.8. DF Cyg is only the third RV Tau star, and the first of the RVb subtype, where the nonlinear analysis indicates that low-dimensional chaos may explain the peculiarities of the pulsation., Comment: 9 pages, 7 figures, accepted in MNRAS
Published: 2018

23. Cepheids with the eyes of photometric space telescopes

Author: András Pál, Emese Plachy, and László Molnár
Subjects: Physics, 010308 nuclear & particles physics, Cepheid variable, QC1-999, FOS: Physical sciences, Astronomy, Field of view, Space (mathematics), 01 natural sciences, Kepler, Polaris, Spitzer Space Telescope, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Space photometric missions have been steadily accumulating observations of Cepheids in recent years, leading to a flow of new discoveries. In this short review we summarize the findings provided by the early missions such as WIRE, MOST, and CoRoT, and the recent results of the Kepler and K2 missions. The surprising and fascinating results from the high-precision, quasi-continuous data include the detection of the amplitude increase of Polaris, and exquisite details about V1154 Cyg within the original Kepler field of view. We also briefly discuss the current opportunities with the K2 mission, and the prospects of the TESS space telescope regarding Cepheids., 5 pages, 2 figures, Proceedings of the 22nd Los Alamos Stellar Pulsation Conference, to be published in EPJ WOC
Published: 2017

24. The additional-mode garden of RR Lyrae stars

Author: Á. L. Juhász, Shashi M. Kanbur, Justin Ortega, Róbert Szabó, Zachary D'Alessandro, László Molnár, Benjamin Kratz, Emese Plachy, and Peter Klagyivik
Subjects: Physics, 010308 nuclear & particles physics, QC1-999, Mode (statistics), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, RR Lyrae variable, 01 natural sciences, Stars, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Space-based photometric missions revealed a surprising abundance of millimagnitude-level additional modes in RR Lyrae stars. The modes that appear in the modulated fundamental-mode (RRab) stars can be ordered into four major categories. Here we present the distribution of these groups in the Petersen diagram, and discuss their characteristics and connections to additional modes observed in other RR Lyrae stars., Comment: 4 pages, 4 figures, proceedings of the Joint TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant Stars 2016", to be published in EPJ WoC
Published: 2017
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25. A modulated RRd star observed by K2

Author: Róbert Szabó, Peter Klagyivik, Emese Plachy, and László Molnár
Subjects: Physics, QC1-999, FOS: Physical sciences, Astrophysics, 010501 environmental sciences, RR Lyrae variable, Star (graph theory), EPIC, Space (mathematics), 01 natural sciences, Amplitude, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Phase modulation, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract: We report the analysis of the double-mode RR Lyrae star EPIC 205209951, the first modulated RRd star observed from space. The amplitude and phase modulation are present in both modes., 2 pages, 3 figures, proceedings of the Joint TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant Stars 2016", to be published in EPJ WoC
Published: 2017

26. Extended Aperture Photometry of K2 RR Lyrae stars

Author: Benjamin J. S. Pope, Emese Plachy, László Molnár, Peter Klagyivik, Attila Bódi, Marek Skarka, Ádám Sódor, Pál Szabó, and Róbert Szabó
Subjects: Physics, 010308 nuclear & particles physics, Cepheid variable, Blazhko effect, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Light curve, 01 natural sciences, Photometry (optics), Stars, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Spitzer Space Telescope, Space and Planetary Science, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The \textit{Kepler} space telescope observed thousands of RR Lyrae stars in the K2 mission. In this paper we present our photometric solutions using extended apertures in order to conserve the flux of the stars to the highest possible extent. With this method we are able to avoid most of the problems that RR Lyrae light curves produced by other pipelines suffer from. For post-processing we apply the K2SC pipeline to our light curves. We provide the EAP (Extended Aperture Photometry) of 432 RR Lyrae stars observed in campaigns 3, 4, 5, and 6. We also provide subclass classifications based on Fourier parameters. We investigated in particular the presence of the Blazhko effect in the stars, and found it to be 44.7\% among the RRab stars, in agreement with results from independent samples. We found that the amplitude and phase modulation in the Blazhko stars may behave rather differently, at least over the length of a K2 Campaign. We also identified four anomalous Cepheid candidates in the sample one of which is potentially the first Blazhko-modulated member of its class., Comment: 20 pages, 13 figures, accepted in ApJS, light curves available at https://konkoly.hu/KIK/data_en.html
Published: 2019
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27. Elimination of long-term variations from chaotic light curves

Author: Emese Plachy and Zoltán Kolláth
Subjects: Physics, Fourier filtering, Space and Planetary Science, Robustness (computer science), Chaotic, Astronomy and Astrophysics, Global flow, Light curve, Biological system, Hilbert–Huang transform, Test data, Term (time)
Abstract: We performed a comparative dynamical investigation of chaotic test data using the global flow reconstruction method. We demonstrate that large-amplitude, long-term variations may have a disturbing effect for the analysis. The Empirical Mode Decomposition method (EMD) and the Fourier filtering were tested to remove the additional variations. Test results show that the elimination of these variations significantly increased the robustness of the reconstructions. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2013
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28. The Kepler Cepheid V1154 Cyg revisited: light curve modulation and detection of granulation

Author: B. Csák, László Molnár, András Pál, Róbert Szabó, Gy. M. Szabó, Ádám Sódor, Emese Plachy, József Benkő, Aliz Derekas, Zs. Bognár, and László Szabados
Subjects: Physics, 010308 nuclear & particles physics, Red giant, Cepheid variable, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, Astrophysics, Light curve, 01 natural sciences, Radial velocity, Stars, symbols.namesake, Fourier transform, Spitzer Space Telescope, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Variable star, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: We present a detailed analysis of the bright Cepheid-type variable star V1154 Cygni using 4 years of continuous observations by the Kepler space telescope. We detected 28 frequencies using standard Fourier transform method.We identified modulation of the main pulsation frequency and its harmonics with a period of ~159 d. This modulation is also present in the Fourier parameters of the light curve and the O-C diagram. We detected another modulation with a period of about 1160 d. The star also shows significant power in the low-frequency region that we identified as granulation noise. The effective timescale of the granulation agrees with the extrapolated scalings of red giant stars. Non-detection of solar-like oscillations indicates that the pulsation inhibits other oscillations. We obtained new radial velocity observations which are in a perfect agreement with previous years data, suggesting that there is no high mass star companion of V1154 Cygni. Finally, we discuss the possible origin of the detected frequency modulations., 10 pages, 9 figures, accepted for publication in MNRAS
Published: 2016

29. G 207-9 and LP 133-144: light curve analysis and asteroseismology of two ZZ Ceti stars

Author: Péter Pápics, M. Paparó, László Molnár, Ádám Sódor, Emese Plachy, E. Verebélyi, and Zs. Bognár
Subjects: Rotation period, Physics, Frequency analysis, 010308 nuclear & particles physics, White dwarf, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Effective temperature, Light curve, 01 natural sciences, Asteroseismology, Instability, law.invention, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, law, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: G 207-9 and LP 133-144 are two rarely observed ZZ Ceti stars located in the middle and close to the blue edge of the ZZ Ceti instability domain, respectively. We aimed to observe them at least during one observing season at Konkoly Observatory with the purpose of extending the list of known pulsation modes for asteroseismic investigations and detect any significant changes in their pulsational behaviour. We determined five and three new normal modes of G 207-9 and LP 133-144, respectively. In LP 133-144, our frequency analysis also revealed that at least at three modes there are actually triplets with frequency separations of ~4 microHz. The rotational period of LP 133-144 based on the triplets is ~42 h. The preliminary asteroseismic fits of G 207-9 predict Teff=12 000 or 12 400 K and M*=0.855-0.870 MSun values for the effective temperature and mass of the star, depending on the assumptions on the spherical degree (l) values of the modes. These results are in agreement with the spectroscopic determinations. In the case of LP 133-144, the best-fitting models prefer Teff=11 800 K in effective temperature and M*>=0.71 MSun stellar masses, which are more than 0.1 MSun larger than the spectroscopic value., 12 pages, 11 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society (2016 June 30)
Published: 2016
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30. 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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31. Uninterrupted optical light curves of main-belt asteroids from the K2 mission

Author: Krisztián Sárneczky, Róbert Szabó, László Molnár, András Pál, Emese Plachy, Cs. Kiss, Gy. M. Szabó, O. Hanyecz, and László L. Kiss
Subjects: Rotation period, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Solar System, 010504 meteorology & atmospheric sciences, Ecliptic, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Light curve, 01 natural sciences, law.invention, Telescope, Spitzer Space Telescope, Space and Planetary Science, Neptune, Asteroid, law, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: Due to the failure of the second reaction wheel, a new mission was conceived for the otherwise healthy Kepler space telescope. In the course of the K2 Mission, the telescope is staring at the plane of the Ecliptic, hence thousands of Solar System bodies cross the K2 fields, usually causing extra noise in the highly accurate photometric data. In this paper we follow the someone's noise is another one's signal principle and investigate the possibility of deriving continuous asteroid light curves, that has been unprecedented to date. In general, we are interested in the photometric precision that the K2 Mission can deliver on moving Solar System bodies. In particular, we investigate space photometric optical light curves of main-belt asteroids. We study the K2 superstamps covering the M35 and Neptune/Nereid fields observed in the long cadence (29.4-min sampling) mode. Asteroid light curves are generated by applying elongated apertures. We use the Lomb-Scargle method to find periodicities due to rotation. We derived K2 light curves of 924 main-belt asteroids in the M35 field, and 96 in the path of Neptune and Nereid. The light curves are quasi-continuous and several days long. K2 observations are sensitive to longer rotational periods than usual ground-based surveys. Rotational periods are derived for 26 main-belt asteroids for the first time. The asteroid sample is dominated by faint (>20 mag) objects. Due to the faintness of the asteroids and the high density of stars in the M35 field, only 4.0% of the asteroids with at least 12 data points show clear periodicities or trend signalling a long rotational period, as opposed to 15.9% in the less crowded Neptune field. We found that the duty cycle of the observations had to reach ~60% in order to successfully recover rotational periods., 9 pages, 9 figures, 6 tables, to be published in Astronomy and Astrophysics, for the full tables of observed asteroids and their rotational parameters see http://www.konkoly.hu/KIK/data_en.html
Published: 2016
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32. 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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33. New results in RR Lyrae modeling: Convective cycles, additional modes and more

Author: Zoltán Kolláth, László Molnár, Róbert Szabó, and Emese Plachy
Subjects: Physics, Convection, Period-doubling bifurcation, Stars, Field (physics), Space and Planetary Science, Mode (statistics), Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Space (mathematics), Asteroseismology
Abstract: Recent theoretical and observational findings breathed new life into the field of RRLyrae stars. The ever more precise and complete measurements of the space asteroseismology missions revealed new details, such as the period doubling and the presence of the additional modes in the stars. Theoretical work also flourished: period doubling was explained and an additional mode has been detected in hydrodynamic models as well. Although the most intriguing mystery, the Blazhko-effect has remained unsolved, new findings indicate that the convective cycle model can be effectively ruled out for short- and medium-period modulations. On the other hand, the plausibility of the radial resonance model is increasing, as more and more resonances are detected both in models and stars (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Published: 2012
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34. The s process in AGB stars as constrained by a large sample of barium stars

Author: Amanda I. Karakas, Sergio Cristallo, Marco Pignatari, Valentina D'Orazi, B. Cseh, D. B. de Castro, Emese Plachy, Claudio B. Pereira, László Molnár, Maria Lugaro, and Róbert Szabó
Subjects: Physics, 010308 nuclear & particles physics, Metallicity, FOS: Physical sciences, White dwarf, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Giant star, 01 natural sciences, Asteroseismology, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Nucleosynthesis, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Asymptotic giant branch, Astrophysics::Earth and Planetary Astrophysics, s-process, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: Context. Barium (Ba) stars are dwarf and giant stars enriched in elements heavier than iron produced by the slow neutron-capture process (s process). They belong to binary systems where the primary star evolved through the asymptotic giant branch (AGB) phase,during which it produced the s-process elements and transferred them onto the secondary, now observed as a Ba star. Aims. We compare the largest homogeneous set of Ba giant star observations of the s-process elements Y, Zr, La, Ce, and Nd with AGB nucleosynthesis models to reach a better understanding of the s process in AGB stars. Methods. By considering the light-s (ls: Y and Zr) heavy-s (hs: La, Ce, and Nd) and elements individually, we computed for the first time quantitative error bars for the different hs-element/ls-element abundance ratios, and for each of the sample stars. We compared these ratios to low-mass AGB nucleosynthesis models. We excluded La from our analysis because the strong La lines in some of the sample stars cause an overestimation and unreliable abundance determination, as compared to the other observed hs-type elements. Results. All the computed hs-type to ls-type element ratios show a clear trend of increasing with decreasing metallicity with a small spread (less than a factor of 3). This trend is predicted by low-mass AGB models where 13C is the main neutron source. The comparison with rotating AGB models indicates the need for the presence of an angular momentum transport mechanism that should not transport chemical species, but significantly reduce the rotational speed of the core in the advanced stellar evolutionary stages. This is an independent confirmation of asteroseismology observations of the slow down of core rotation in giant stars, and of rotational velocities of white dwarfs lower than predicted by models without an extra angular momentum transport mechanism., Comment: 15 pages, 7 figures, accepted for publication in Astronomy and Astrophysics
Published: 2018
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35. HD 50844: a new look atδScuti stars from CoRoT space photometry

Author: L. Mantegazza, K. Uytterhoeven, Eric Michel, M. Auvergne, Frédéric Baudin, C. Catala, E. Rodriguez, Ennio Poretti, R. Samadi, Juan Carlos Suárez, Susana Martín-Ruiz, Monica Rainer, M. Alvarez, Annie Baglin, Laure Lefèvre, Emese Plachy, R. Garrido, Péter Pápics, Philippe Mathias, M. Paparó, E. Niemczura, W. Zima, A. Moya, Pedro J. Amado, INAF-Osservatorio Astronomico di Brera (INAF-OAB), 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), Instituto de Astrofisica de Andalucia, CSIC (IAA), Astronomical Institute, University of Wroclaw, Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Observatorio Astronómico Nacional, Instituto de Astronomía, Universidad Nacional Autónoma de México, Laboratoire Hippolyte Fizeau (FIZEAU), 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), and Konkoly Observatory, Research Center for Astronomy and Earth Sciences
Subjects: Physics, Frequency analysis, Flux, Astronomy, Astronomy and Astrophysics, Context (language use), Astrophysics, Light curve, Spectral line, law.invention, Photometry (optics), Stars, Amplitude, [SDU]Sciences of the Universe [physics], Space and Planetary Science, law, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: International audience; Context: Aims: This work presents the results obtained by CoRoT on HD 50844, the only delta Sct star observed in the CoRoT initial run (57.6 d). The aim of these CoRoT observations was to investigate and characterize for the first time the pulsational behaviour of a delta Sct star, when observed at a level of precision and with a much better duty cycle than from the ground. Methods: The 140 016 datapoints were analysed using independent approaches (SigSpec software and different iterative sine-wave fittings) and several checks performed (splitting of the timeseries in different subsets, investigation of the residual light curves and spectra). A level of 10-5 mag was reached in the amplitude spectra of the CoRoT timeseries. The space monitoring was complemented by ground-based high-resolution spectroscopy, which allowed the mode identification of 30 terms. Results: The frequency analysis of the CoRoT timeseries revealed hundreds of terms in the frequency range 0-30 d-1. All the cross-checks confirmed this new result. The initial guess that delta Sct stars have a very rich frequency content is confirmed. The spectroscopic mode identification gives theoretical support since very high-degree modes (up to l=14) are identified. We also prove that cancellation effects are not sufficient in removing the flux variations associated to these modes at the noise level of the CoRoT measurements. The ground-based observations indicate that HD 50844 is an evolved star that is slightly underabundant in heavy elements, located on the Terminal Age Main Sequence. Probably due to this unfavourable evolutionary status, no clear regular distribution is observed in the frequency set. The predominant term (f_1=6.92 d-1) has been identified as the fundamental radial mode combining ground-based photometric and spectroscopic data. Conclusions
Published: 2009
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36. Preliminary Results in White Dwarf Research by a New Group

Author: Gy. Kerekes, N. Sztankó, Péter Pápics, E. Bokor, Zs. Bognár, László Molnár, M. Paparo, Emese Plachy, and A. M. Bokor
Subjects: Physics, Group (periodic table), Astronomy, White dwarf, Astrophysics
Published: 2009
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37. An RR Lyrae family portrait: 33 stars observed in Pisces with K2-E2

Author: E. Guggenberger, Zoltán Kolláth, P. Moskalik, Radosław Poleski, László Molnár, Emese Plachy, Katrien Kolenberg, Radosław Smolec, J. M. Nemec, and Róbert Szabó
Subjects: Physics, 010308 nuclear & particles physics, K-type main-sequence star, media_common.quotation_subject, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Light curve, 01 natural sciences, variables: RR Lyrae [stars], Stars, Spitzer Space Telescope, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sky, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), media_common
Abstract: A detailed analysis is presented of 33 RR Lyrae stars in Pisces observed with the Kepler space telescope over the 8.9-day long K2 Two-Wheel Concept Engineering Test. The sample includes not only fundamental-mode and first overtone (RRab and RRc) stars but the first two double-mode (RRd) stars that Kepler detected and the only modulated first-overtone star ever observed from space so far. The precision of the extracted K2 light curves made it possible to detect low-amplitude additional modes in all subtypes. All RRd and non-modulated RRc stars show the additional mode at P_X/P_1~0.61 that was detected in previous space-based photometric measurements. A periodicity longer than the fundamental mode was tentatively identified in one RRab star that might belong to a gravity mode. We determined the photometric [Fe/H] values for all fundamental-mode stars and provide the preliminary results of our efforts to fit the double-mode stars with non-linear hydrodynamic pulsation models. The results from this short test run indicate that the K2 mission will be, and has started to be, an ideal tool to expand our knowledge about RR Lyrae stars. As a by-product of the target search and analysis, we identified 165 bona-fide double-mode RR Lyrae stars from the Catalina Sky Survey observations throughout the sky, 130 of which are new discoveries., 15 pages, 14 figures, accepted for publication in MNRAS. Data files can be accessed at http://konkoly.hu/KIK/data.html
Published: 2015

38. Dynamical investigation of modulated Kepler RR Lyrae stars

Author: Zoltán Kolláth, József Benkő, Róbert Szabó, Emese Plachy, and László Molnár
Subjects: Physics, Data processing, 010308 nuclear & particles physics, Pipeline (computing), QC1-999, Chaotic, Astronomy, Astrophysics, RR Lyrae variable, 01 natural sciences, Kepler, 0103 physical sciences, Modulation (music), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Variable star, 010303 astronomy & astrophysics
Abstract: We performed a non-linear dynamical analysis on the Blazhko modulation for the first time. Our results suggest that the detection of chaotic nature behind the phenomenon is limited by the instrumental effects and the data processing problems of the Kepler pipeline concerning high-amplitude variable stars.
Published: 2015

39. Classical variables in the era of space photometric missions

Author: Emese Plachy, László Molnár, Róbert Szabó, and József Benkő
Subjects: Physics, Cepheid variable, QC1-999, Astrophysics::Instrumentation and Methods for Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, RR Lyrae variable, Space (mathematics), 01 natural sciences, Kepler, 010309 optics, Stars, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: The space photometric missions like CoRoT and Kepler transformed our view of pulsating stars, including the well-known RR Lyrae and Cepheid classes. The K2, TESS and PLATO missions will expand these investigations to larger sample sizes and to specific stellar populations.
Published: 2015

40. The K2 RR Lyrae Survey

Author: Emese Plachy, Katrien Kolenberg, Peter Klagyivik, Róbert Szabó, O. Hanyecz, László Molnár, and KASC RR Lyrae Cepheid Working Grp
Subjects: Physics, 010308 nuclear & particles physics, QC1-999, Blazhko effect, Ecliptic, Astronomy, Context (language use), Astrophysics, RR Lyrae variable, 01 natural sciences, 0103 physical sciences, Variable star, Variation (astronomy), 010303 astronomy & astrophysics
Abstract: We have initiated a large survey with K2 to observe thousands of RR Lyrae stars along the Ecliptic. The high photometric precision and the 80-90-day continuous coverage will allow us to investigate the light variation of these galactic structure tracer variable stars with an unprecedented detail. The survey will help us to conduct a thorough statistical study of RR Lyrae pulsation dynamics including old and recently discovered dynamical phenomena, like resonances, non-radial modes, period doubling, and the Blazhko effect. We describe the survey, present the first results and discuss the prospects of combining the K2 RR Lyrae survey, Gaia, and LSST in the context of galactic structure studies.
Published: 2017
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41. Extended Aperture Photometry of K2 RR Lyrae stars

Author: Emese Plachy, P. Klagyivik, Á. Sódor, László Molnár, and Róbert Szabó
Subjects: Physics, 010308 nuclear & particles physics, Aperture, QC1-999, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Field of view, Astrophysics, RR Lyrae variable, Light curve, 01 natural sciences, Photometry (optics), Stars, Astrophysics - Solar and Stellar Astrophysics, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: We present the method of the Extended Aperture Photometry (EAP) that we applied to K2 RR Lyrae stars. Our aim is to minimize the instrumental variations of attitude control maneuvers by using apertures that cover the positional changes in the field of view thus contain the stars during the whole observation. We present example light curves that we compared to the light curves from the K2 Systematics Correction (K2SC) pipeline applied to the automated Single Aperture Photometry (SAP) and to the Pre-search Data Conditioning Simple Aperture Photometry (PDCSAP) data., 3 pages, 1 figure, proceedings of the Joint TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant Stars 2016", to be published in EPJ WoC
Published: 2017
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42. Nonlinear dynamical analysis of the Blazhko effect with the Kepler space telescope: the case of V783 Cyg

Author: László Molnár, Zoltán Kolláth, Róbert Szabó, Emese Plachy, and József Benkő
Subjects: Physics, Blazhko effect, Chaotic, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Photometry (optics), Stars, Nonlinear system, Amplitude, Spitzer Space Telescope, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present a detailed nonlinear dynamical investigation of the Blazhko modulation of the Kepler RR Lyrae star V783 Cyg (KIC 5559631). We used different techniques to produce modulation curves, including the determination of amplitude maxima, the O-C diagram and the analytical function method. We were able to fit the modulation curves with chaotic signals with the global flow reconstruction method. However, when we investigated the effects of instrumental and data processing artefacts, we found that the chaotic nature of the modulation can not be proved because of the technical problems of data stitching, detrending and sparse sampling. Moreover, we found that a considerable part of the detected cycle-to-cycle variation of the modulation may originate from these effects. According to our results, even the four-year-long, unprecedented Kepler space photometry of V783 Cyg is too short for a reliable nonlinear dynamical analysis aiming at the detection of chaos from the Blazhko modulation. We estimate that two other stars could be suitable for similar analysis in the Kepler sample and in the future TESS and PLATO may provide additional candidates., Comment: 9 pages, 12 figures, accepted for publication in MNRAS
Published: 2014
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43. Long Time-Scale Behaviour of the Blazhko Effect from rectified Kepler Data

Author: László Molnár, Emese Plachy, Róbert Szabó, Zoltán Kolláth, and József Benkő
Subjects: Physics, 010308 nuclear & particles physics, Blazhko effect, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Light curve, 01 natural sciences, Amplitude modulation, Stars, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Modulation (music), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Variable star, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: In order to benefit from the 4-year unprecedented precision of the Kepler data, we extracted light curves from the pixel photometric data of the Kepler space telescope for 15 Blazhko RR Lyrae stars. For collecting all the flux from a given target as accurately as possible, we defined tailor-made apertures for each star and quarter. In some cases the aperture finding process yielded sub-optimal result, because some flux have been lost even if the aperture contains all available pixels around the star. This fact stresses the importance of those methods that rely on the whole light curve instead of focusing on the extrema (O-C diagrams and other amplitude independent methods). We carried out detailed Fourier analysis of the light curves and the amplitude independent O-C diagram. We found 12 (80%) multiperiodically modulated stars in our sample. This ratio is much higher than previously found. Resonant coupling between radial modes, a recent theory to explain of the Blazhko effect, allows single, multiperiodic or even chaotic modulations. Among the stars with two modulations we found three stars (V355 Lyr, V366 Lyr and V450 Lyr) where one of the periods dominate in amplitude modulation, but the other period has larger frequency modulation amplitude. The ratio between the primary and secondary modulation periods is almost always very close to ratios of small integer numbers. It may indicate the effect of undiscovered resonances. Furthermore, we detected the excitation of the second radial overtone mode $f_2$ for three stars where this feature was formerly unknown. Our data set comprises the longest continuous, most precise observations of Blazhko RR Lyrae stars ever published. These data which is made publicly available will be unprecedented for years to come., 19 pages, 17 figures, accepted for publication in Astrophys. J. Suppl. Rectified data are here: http://www.konkoly.hu/KIK/data.html
Published: 2014

44. More frequencies of KUV 02464+3239

Author: N. Sztankó, Gy. Kerekes, László Molnár, M. Paparó, E. Bokor, Emese Plachy, A. Már, P. Pápics, and Zs. Bognár
Subjects: Physics, Subharmonic, Amplitude, Space and Planetary Science, Harmonics, Long period, Astrophysics::Solar and Stellar Astrophysics, White dwarf, Astronomy and Astrophysics, Astrophysics, Light curve, Instability strip
Abstract: Preliminary results on KUV 02464+3239, a pulsating DA white dwarf are presented. Located near the red edge of the DAV instability strip, KUV 02464+3239 shows large amplitude and long period pulsation modes. Up to now only one mode was known from a 50-minute-long light curve. Our more extended observations allowed the identification of three additional frequencies. The presence of previously known harmonics were confirmed and weak subharmonics are also noticeable at some parts of the light curve. This suggests the dominance of nonlinear pulsation effects from time to time., Comment: 3 pages, 3 eps figures; has been accepted for publication in Astronomische Nachrichten (Vol. 8, 2007), proceedings of the British-Hungarian-French N+N+N Workshop for Young Researchers
Published: 2007
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45. Low-dimensional chaos in RR Lyrae models

Author: László Molnár, Emese Plachy, and Zoltán Kolláth
Subjects: Lyapunov function, Physics, Period-doubling bifurcation, Overtone, Chaotic, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Light curve, symbols.namesake, Fractal, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Attractor, symbols, Astrophysics::Solar and Stellar Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: The recent precise photometric observations and successes of the modelling efforts transformed our picture of the pulsation of RR Lyrae stars. The discovery of additional frequencies and the period doubling phenomenon revealed that a significant interaction may occur between pulsational modes. The signs of irregularities were detected both in observed light curves and hydrodynamic calculations. In this paper we present the analysis of four peculiar hydrodynamic model solutions. All four solutions were found to be chaotic. The fractal (Lyapunov) dimensions of their attractors were calculated to be ~2.2. We also investigated possible resonances between the fundamental mode and the first overtone in the dynamical neighbourhood of these models. The most important is the 6:8 resonance that was also detected in the Kepler observations of RR Lyrae itself. These results reveal that the investigation of chaotic models is important in discovering and understanding resonances in RR Lyrae stars., 7 pages, 8 figures, accepted for publication in MNRAS
Published: 2013

46. Asteroseismology of the ZZ Ceti star HS 0507+0434B★

Author: László Molnár, S. L. Kim, M. Chevreton, N. Dolez, Y. P. Zhang, G. Vauclair, M. Alvarez, Yin-Bi Li, X. H. Yang, Stéphane Charpinet, Li Chen, C. Li, Emese Plachy, Jie Su, Jian-Ning Fu, Raul Michel, L. Fox Machado, Laboratoire Astrophysique de Toulouse-Tarbes (LATT), 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), Laboratoire d'Astrophysique de l'Observatoire Midi-Pyrénées (LATT), Department of Electronic and Electrical Engineering, Pohang University of Science and Technology (POSTECH), 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), 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: FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Rotation, 01 natural sciences, Asteroseismology, Luminosity, symbols.namesake, Sine wave, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, Physics, [PHYS]Physics [physics], 010308 nuclear & particles physics, Astronomy, White dwarf, Astronomy and Astrophysics, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Fourier analysis, symbols, Astrophysics::Earth and Planetary Astrophysics, Instability strip, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The pulsating DA white dwarfs (ZZ Ceti stars) are $g$-mode non-radial pulsators. Asteroseismology provides strong constraints on their global parameters and internal structure. Since all the DA white dwarfs falling in the ZZ Ceti instability strip do pulsate, the internal structure derived from asteroseismology brings knowledge for the DA white dwarfs as a whole group. HS 0507+0434B is one of the ZZ Ceti stars which lies approximately in the middle of the instability strip for which we have undertaken a detailed asteroseismological study. We carried out multisite observation campaigns in 2007 and from December 2009 to January 2010. In total, 206 hours of photometric time-series have been collected. They have been analysed by means of Fourier analysis and simultaneous multi-frequency sine-wave fitting. In total, 39 frequency values are resolved including 6 triplets and a number of linear combinations. We identify the triplets as $\ell$=1 $g$-modes split by rotation. We derived the period spacing, the rotational splitting and the rotation rate. From the comparison of the observed periods with the theoretical periods of a series of models we estimate the fundamental parameters of the star: its total mass M$_{*}$/M$_{\odot}$ = 0.675, its luminosity L/L$_{\odot}$=3.5$\times 10^{-3}$, and its hydrogen mass fraction M$_{H}$/M$_{*}$= 10$^{-8.5}$., Comment: 12 pages,8 figures, accepted for publication in MNRAS
Published: 2013
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47. Multimode pulsation of the ZZ Ceti star GD 154

Author: M. Paparó, László Molnár, Zs. Bognár, Emese Plachy, and Paul A. Bradley
Subjects: Physics, Rotation period, Multi-mode optical fiber, White dwarf, FOS: Physical sciences, Astronomy and Astrophysics, Dominant frequency, Astrophysics, Trapping, Star (graph theory), Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Normal mode, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We present the results of a comparative period search on different time-scales and modelling of the ZZ Ceti (DAV) star GD 154. We determined six frequencies as normal modes and four rotational doublets around the ones having the largest amplitude. Two normal modes at 807.62 and 861.56 microHz have never been reported before. A rigorous test revealed remarkable intrinsic amplitude variability of frequencies at 839.14 and 861.56 microHz over a 50 d time-scale. In addition, the multimode pulsation changed to monoperiodic pulsation with an 843.15 microHz dominant frequency at the end of the observing run. The 2.76 microHz average rotational split detected led to a determination of a 2.1 d rotational period for GD 154. We searched for model solutions with effective temperatures and log g close to the spectroscopically determined ones. The best-fitting models resulting from the grid search have M_H between 6.3 x 10^-5 and 6.3 x 10^-7 M*, which means thicker hydrogen layer than the previous studies suggested. Our investigations show that mode trapping does not necessarily operate in all of the observed modes and the best candidate for a trapped mode is at 2484 microHz., Comment: 11 pages, 11 figures, accepted for publication in MNRAS
Published: 2013
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48. On the interchange of alternating-amplitude pulsation cycles

Author: László Molnár, Emese Plachy, Zoltán Kolláth, József Benkő, Katrien Kolenberg, Guzik, JA, Chaplin, WJ, Handler, G, and Pigulski, A
Subjects: Physics, Amplitude, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, RR Lyrae variable, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: We characterized the time intervals between the interchanges of the alternating high- and low-amplitude extrema of three RV Tauri and three RR Lyrae stars., Comment: 2 pages, Proceedings of the 301st IAU Symposium, Precision Asteroseismology, August 2013
Published: 2013
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49. 5th Workshop of Young Researchers in Astronomy & Astrophysics

Author: Emese Forgács-Dajka, Emese Plachy, and László Molnár
Subjects: History, Engineering, business.industry, media_common.quotation_subject, Astronomy, Astrophysics, Computer Science Applications, Education, Pleasure, Hospitality, Christian ministry, China, business, Phd students, media_common
Abstract: The 5th Workshop of Young Researchers in Astronomy and Astrophysics was held on 2–4 September 2009 at the Eotvos University in Budapest, Hungary. This meeting fits into a conference series which can already be considered a tradition where the younger generation has the opportunity to present their work. The event was also a great opportunity for senior astronomers and physicists to form new connections with the next generation of researchers. The selection of invited speakers concentrated on the researchers currently most active in the field, mostly on a post-doctoral/tenure/fresh faculty position level. A number of senior experts and PhD students were also invited. As the conference focused on people rather than a specific field, various topics from theoretical physics to planetology were covered in three days. The programme was divided into six sections: Physics of the Sun and the Solar System Gravity and high-energy physics Galactic and extragalactic astronomy, cosmology Celestial mechanics and exoplanets Infrared astronomy and young stars Variable stars We had the pleasure of welcoming 10 invited review talks from senior researchers and 42 contributed talks and a poster from the younger generation. Participants also enjoyed the hospitality of the pub Pal at the Palvolgyi-cave after giving, hearing and disputing countless talks. Brave souls even descended to the unbuilt, adventurous Matyasvolgyi-cave. Memories of the conference were shadowed though. Peter Csizmadia, one of our participants and three other climbers attempted a first ever ascent to the Ren Zhong Feng peak in Sichuan, China, but they never returned from the mountains. Peter departed to China shortly after the conference, with best wishes from participants and friends. We dedicate this volume to his memory. The organisers thankthe Physics Doctoral School of Eotvos University for its hospitality. The workshop was supported by the Mecenatura and Polanyi Mihaly Programmes of the National Office for Research and Technology (NKTH) and the Ministry of Education and Culture (OKM) of Hungary. Emese Forgacs-Dajka, Emese Plachy and Laszlo Molnar
Published: 2010
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50. Testing the global flow reconstruction method on coupled chaotic oscillators

Author: Zoltán Kolláth and Emese Plachy
Subjects: Lyapunov function, History, Mathematical analysis, Light curve, Computer Science Applications, Education, Connection (mathematics), symbols.namesake, Classical mechanics, Fourier transform, Dimension (vector space), Robustness (computer science), symbols, Global flow, Time series, Mathematics
Abstract: Irregular behaviour of pulsating variable stars may occur due to low dimensional chaos. To determine the quantitative properties of the dynamics in such systems, we apply a suitable time series analysis, the global flow reconstruction method. The robustness of the reconstruction can be tested through the resultant quantities, like Lyapunov dimension and Fourier frequencies. The latter is specially important as it is directly derivable from the observed light curves. We have performed tests using coupled Rossler oscillators to investigate the possible connection between those quantities. In this paper we present our test results.
Published: 2010
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