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1. Spectroscopic mode identification of γ Doradus stars

Author: Brunsden E., Pollard K.R., Cottrell P.L., Wright D.J., and Cat P. De
Subjects: Physics, QC1-999
Abstract: The g-mode pulsations in γ Doradus stars are identified using time-series colour photometry and high-resolution spectroscopy. For 22 class members the pulsational frequencies and modes are compared. Ground-based spectroscopic and photometric results show good agreement. The prevalence of (1, |1|) modes is noted and examined.
Published: 2017
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2. Low-frequency gravity waves in blue supergiants revealed by high-precision space photometry

Author: Bowman, D.M., Burssens, Siemen, Pedersen, M.G., Johnston, Cole, Aerts, Conny, Buysschaert, B., White, T.R., Cat, P. de, Bowman, D.M., Burssens, Siemen, Pedersen, M.G., Johnston, Cole, Aerts, Conny, Buysschaert, B., White, T.R., and Cat, P. de
Abstract: Contains fulltext : 206194pub.pdf (publisher's version ) (Closed access) Contains fulltext : 206194pre.pdf (preprint version ) (Open Access)
Published: 2019

3. K2 photometry and HERMES spectroscopy of the blue supergiant ρ Leo: rotational wind modulation and low-frequency waves★

Author: Aerts, C., Bowman, D.M., S’imon-D’iaz, S., Buysschaert, B., Johnston, C., Moravveji, E., Beck, P.G., Cat, P. de, Triana, S., Aigrain, S., Castro, N., Huber, D., White, T., Aerts, C., Bowman, D.M., S’imon-D’iaz, S., Buysschaert, B., Johnston, C., Moravveji, E., Beck, P.G., Cat, P. de, Triana, S., Aigrain, S., Castro, N., Huber, D., and White, T.
Abstract: Contains fulltext : 184317.pdf (publisher's version ) (Open Access)
Published: 2018

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

Author: Clementini, G. Eyer, L. Ripepi, V. Marconi, M. Muraveva, T. Garofalo, A. Sarro, L.M. Palmer, M. Luri, X. Molinaro, R. Rimoldini, L. Szabados, L. Musella, I. Anderson, R.I. Prusti, T. De Bruijne, J.H.J. Brown, A.G.A. Vallenari, A. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Drimmel, R. Høg, E. Katz, D. Lattanzi, M.G. O'Mullane, W. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Perryman, M. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Barrado, N.Y. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Durán, J. Dzigan, Y. Edvardsson, B. Enke, H. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Krone-Martins, A. Kudryashova, M. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lorenz, D. Macdonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Reylé, C. Ribeiro, R.A. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Shih, I.-C. Smareglia, R. Smart, R.L. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Wevers, T. Wyrzykowski, L. Yoldas, A. Zerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. Lebouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. O'Flaherty, K.S. Ocvirk, P. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'Homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. StraizYs, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Abstract: Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σΩ/Ω< 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with σΩ/Ω< 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with σΩ/Ω< 0.5). The new relations were computed using multi-band (V,I,J,Ks) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and MV- [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. © ESO, 2017.
Published: 2017

5. The Gaia mission

Author: Prusti, T. De Bruijne, J.H.J. Brown, A.G.A. Vallenari, A. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. Mignard, F. Milligan, D.J. Panem, C. Poinsignon, V. Pourbaix, D. Randich, S. Sarri, G. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Drimmel, R. Høg, E. Katz, D. Lattanzi, M.G. O'Mullane, W. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Clementini, G. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Atzei, A. Ayache, L. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Baroni, M. Barrado Y Navascués, D. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bellei, G. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bouy, H. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Budnik, F. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Charvet, P. Chassat, F. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Collins, P. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Marco, F. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Durán, J. Dzigan, Y. Ecale, E. Edvardsson, B. Enke, H. Erdmann, M. Escolar, D. Espina, M. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Faye, F. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Furnell, R. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garé, P. Garofalo, A. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Kowalczyk, A. Krone-Martins, A. Kudryashova, M. Kull, I. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lopez-Lozano, A. Lorenz, D. Loureiro, T. MacDonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marie, J. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Mestre, A. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, R. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Monteiro, D. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morley, T. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Paulsen, T. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pereira, J. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Renk, F. Reylé, C. Ribeiro, R.A. Rimoldini, L. Ripepi, V. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Rudolph, A. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schnorhk, A. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Serpell, E. Shih, I.-C. Smareglia, R. Smart, R.L. Smith, C. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Werner, D. Wevers, T. Whitehead, G. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. Lebouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. Ocvirk, P. O'Flaherty, K.S. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Palmer, M. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Sembay, S. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. Straižys, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Subjects: instruments [space vehicles], proper motions, parallaxes, astrometry, telescopes, structure [Galaxy]
Abstract: Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page.http://www.cosmos.esa.int/gaia
Published: 2016
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6. Gaia Data Release 1: Summary of the astrometric, photometric, and survey properties

Author: Brown, A.G.A. Vallenari, A. Prusti, T. De Bruijne, J.H.J. Mignard, F. Drimmel, R. Babusiaux, C. Bailer-Jones, C.A.L. Bastian, U. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Jordi, C. Katz, D. Klioner, S.A. Lammers, U. Lindegren, L. Luri, X. O'Mullane, W. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Van Leeuwen, F. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Høg, E. Lattanzi, M.G. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Perryman, M. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Clementini, G. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'Oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Barrado Y Navascués, D. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bouy, H. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Duran, J. Dzigan, Y. Edvardsson, B. Enke, H. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Krone-Martins, A. Kudryashova, M. Kull, I. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lorenz, D. MacDonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, R. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Reylé, C. Ribeiro, R.A. Rimoldini, L. Ripepi, V. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Shih, I.-C. Smareglia, R. Smart, R.L. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Van Leeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Wevers, T. Wyrzykowski, Ł. Yoldas, A. Žerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. LeBouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. Ocvirk, P. O'Flaherty, K.S. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Palmer, M. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Sembay, S. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. Straižys, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Abstract: Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr-1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr-1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data. © ESO, 2016.
Published: 2016

7. Analysis of MERCATOR data - Part II: variable A & F stars is of MERCATOR data - Part I: variable B stars

Author: Cuypers, J., Goossens, K., Schoenaers, C., Cat, P. de, Aerts, C.C., Briquet, M., Saesen, S., Yakut, K., Scuflaire, R., and Dupret, M.A.
Subjects: Astronomy
Abstract: Contains fulltext : 36085.pdf (Publisher’s version ) (Open Access) For a few decades, a large international community is working at the development of stellar seismology, intending to open a new window on the structure and evolution of stars, with the necessary parallel development of new observational techniques, modeling tools and methods for diagnostics and interpretation. This new window is associated with new observables, characterizing the oscillations (frequencies, amplitudes, line profiles,...) which are sensitive to the stellar interior and thus very complementary with surface observables, associated to astrometry, spectropolarimetry or interferometry. We re-classified 31 variable B stars which were observed more than 50 times in the Geneva photometric system with the p7 photometer attached to the MERCATOR telescope (La Palma) during its first 3 years of scientific observations. HD 89688 is a possible beta Cephei/slowly pulsating B star hybrid and the main mode of the COROT target HD 180642 shows non-linear effects. The Maia candidates are re-classified as either ellipsoidal variables or spotted stars. Although the mode identification is still
Published: 2006

8. Pulsation versus metallicism in Am stars as revealed by LAMOST and WASP

Author: Smalley, B, Antoci, V, Holdsworth, Daniel Luke, Kurtz, D W, Murphy, S J, Cat, P De, Anderson, D R, Catanzaro, G, Collier Cameron, A, Hellier, C, Maxted, P F L, Norton, A J, Pollacco, D, Ripepi, V, Smalley, B, Antoci, V, Holdsworth, Daniel Luke, Kurtz, D W, Murphy, S J, Cat, P De, Anderson, D R, Catanzaro, G, Collier Cameron, A, Hellier, C, Maxted, P F L, Norton, A J, Pollacco, D, and Ripepi, V
Abstract: We present the results of a study of a large sample of A and Am stars with spectral types from Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and light curves from Wide Area Search for Planets (WASP). We find that, unlike normal A stars, δ Sct pulsations in Am stars are mostly confined to the effective temperature range 6900 < Teff < 7600 K. We find evidence that the incidence of pulsations in Am stars decreases with increasing metallicism (degree of chemical peculiarity). The maximum amplitude of the pulsations in Am stars does not appear to vary significantly with metallicism. The amplitude distributions of the principal pulsation frequencies for both A and Am stars appear very similar and agree with results obtained from Kepler photometry. We present evidence that suggests turbulent pressure is the main driving mechanism in pulsating Am stars, rather than the κ-mechanism, which is expected to be suppressed by gravitational settling in these stars.
Published: 2017
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9. Kepler observations of the variability in B-type stars

Author: Balona, Luis, Pigulski, Andrzej, Cat, P. De, Handler, Gerald, Gutiérrez, Juan, Engelbrecht, C. A., Frescura, F., Briquet, Maryline, Cuypers, J., Daszynska-Daszkiewicz, J., Degroote, Pieter, Dukes, R. J., Garcia, Rafael A., Green, E. M., Heber, U., Kawaler, Steven D., Lehmann, H., Leroy, A., Molenda-Zakowicz, Joanna, Neiner, Coralie, Noels, Arlette, Nuspl, J., Østensen, R., Pricopi, D., Roxburgh, Ian W., Salmon, Sébastien, Smith, Myron A., Suárez, Juan Carlos, Suran, M. D., Szabó, Robert, Uytterhoeven, K., Christensen-Dalsgaard, Jörgen, Kjeldsen, Hans, Caldwell, Douglas A., Girouard, F. R., Sanderfer, Dwight T., South African Astronomical Observatory (SAAO), Instytut Astronomiczny, Uniwersytet Wroclawski, Koninklijke Sterrenwacht van België, Institut für Astronomie, Universität Wien (IfA), Instituto de Astrofisica de Andalucia, CSIC (IAA), 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), Etoile, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Physics, University of Johannesburg, School of Physics, University of the Witwatersrand, Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Department of Physics and Astronomy, College of Charleston, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Steward Observatory, University of Arizona, Dr. Karl Remeis-Sternwarte, Astronomisches Institut, Universität Erlangen-Nuremberg, Department of Physics and Astronomy, Iowa State University, Thüringer Landessternwarte, Tautenburg Observatory, Institut d'Astrophysique, Géophysique et Océanographie, Université de Liège, Queen Mary University of London, Mile End Road, Astronomical Institute of the Romanian Academy, Bucharest, Space Telescope Science Institute (STScI), Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Department of Physics and Astronomy, Aarhus University, SETI Institute, NASA Ames Research Center, Moffett Field, and Orbital Sciences Corporation, NASA Ames Research Center, Moffett Field
Subjects: Astrophysics - Solar and Stellar Astrophysics, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract: The analysis of the light curves of 48 B-type stars observed by Kepler is presented. Among these are 15 pulsating stars, all of which show low frequencies characteristic of SPB stars. Seven of these stars also show a few weak, isolated high frequencies and they could be considered as SPB/beta Cep hybrids. In all cases the frequency spectra are quite different from what is seen from ground-based observations. We suggest that this is because most of the low frequencies are modes of high degree which are predicted to be unstable in models of mid-B stars. We find that there are non-pulsating stars within the beta Cep and SPB instability strips. Apart from the pulsating stars, we can identify stars with frequency groupings similar to what is seen in Be stars but which are not Be stars. The origin of the groupings is not clear, but may be related to rotation. We find periodic variations in other stars which we attribute to proximity effects in binary systems or possibly rotational modulation. We find no evidence for pulsating stars between the cool edge of the SPB and the hot edge of the delta Sct instability strips. None of the stars show the broad features which can be attributed to stochastically-excited modes as recently proposed. Among our sample of B stars are two chemically peculiar stars, one of which is a HgMn star showing rotational modulation in the light curve., Comment: 19 pages, 11 figures, 4 tables
Published: 2011
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10. Spectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type stars

Author: Niemczura, E., Murphy, S.J., Smalley, B., Uytterhoeven, K., Pigulski, A., Lehmann, H., Bowman, D.M., Catanzaro, G., Aarle, E. van, Bloemen, S., Briquet, M., Cat, P. de, Drobek, D., Eyer, L., Gameiro, J.F.S., Gorlova, N., Kamiński, K., Lampens, P., Marcos-Arenal, P., Pápics, P.I., Vandenbussche, B., Winckel, H. van, Stȩślicki, M., Fagas, M., Niemczura, E., Murphy, S.J., Smalley, B., Uytterhoeven, K., Pigulski, A., Lehmann, H., Bowman, D.M., Catanzaro, G., Aarle, E. van, Bloemen, S., Briquet, M., Cat, P. de, Drobek, D., Eyer, L., Gameiro, J.F.S., Gorlova, N., Kamiński, K., Lampens, P., Marcos-Arenal, P., Pápics, P.I., Vandenbussche, B., Winckel, H. van, Stȩślicki, M., and Fagas, M.
Abstract: Contains fulltext : 141190.pdf (preprint version ) (Open Access)
Published: 2015

11. Lamost observations in the kepler field. I. Database of low-resolution spectra*

Author: Cat, P. De, Fu, J. N., Ren, A. B., Yang, X. H., Shi, J. R., Luo, A. L., Yang, M., Wang, J. L., Zhang, H. T., Shi, H. M., Zhang, W., Dong, Subo, Catanzaro, G., Corbally, C. J., Frasca, A., Gray, R. O., Żakowicz, J. Molenda, Uytterhoeven, K., Briquet, M., Bruntt, H., Frandsen, S., Kiss, L., Kurtz, Donald Wayne, Marconi, M., Niemczura, E., Østensen, R. H., Ripepi, V., Smalley, B., Southworth, J., Szabó, R., Telting, J. H., Karoff, C., Aguirre, V. Silva, Wu, Y., Hou, Y. H., Jin, G., Zhou, X. L., Cat, P. De, Fu, J. N., Ren, A. B., Yang, X. H., Shi, J. R., Luo, A. L., Yang, M., Wang, J. L., Zhang, H. T., Shi, H. M., Zhang, W., Dong, Subo, Catanzaro, G., Corbally, C. J., Frasca, A., Gray, R. O., Żakowicz, J. Molenda, Uytterhoeven, K., Briquet, M., Bruntt, H., Frandsen, S., Kiss, L., Kurtz, Donald Wayne, Marconi, M., Niemczura, E., Østensen, R. H., Ripepi, V., Smalley, B., Southworth, J., Szabó, R., Telting, J. H., Karoff, C., Aguirre, V. Silva, Wu, Y., Hou, Y. H., Jin, G., and Zhou, X. L.
Abstract: The nearly continuous light curves with micromagnitude precision provided by the space mission Kepler are revolutionizing our view of pulsating stars. They have revealed a vast sea of low-amplitude pulsation modes that were undetectable from Earth. The long time base of Kepler light curves allows for the accurate determination of the frequencies and amplitudes of pulsation modes needed for in-depth asteroseismic modeling. However, for an asteroseismic study to be successful, the ﬁrst estimates of stellar parameters need to be known and they cannot be derived from the Kepler photometry itself. The Kepler Input Catalog provides values for the effective temperature, surface gravity, and metallicity, but not always with sufﬁcient accuracy. Moreover, information on the chemical composition and rotation rate is lacking. We are collecting low-resolution spectra for objects in the Kepler ﬁeld of view with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, Xinglong observatory, China). All of the requested ﬁelds have now been observed at least once. In this paper, we describe those observations and provide a useful database for the whole astronomical community
Published: 2015

12. LAMOST OBSERVATIONS IN THEKEPLERFIELD: SPECTRAL CLASSIFICATION WITH THE MKCLASS CODE

Author: Gray, R. O., primary, Corbally, C. J., additional, Cat, P. De, additional, Fu, J. N., additional, Ren, A. B., additional, Shi, J. R., additional, Luo, A. L., additional, Zhang, H. T., additional, Wu, Y., additional, Cao, Z., additional, Li, G., additional, Zhang, Y., additional, Hou, Y., additional, and Wang, Y., additional
Published: 2015
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13. LAMOST OBSERVATIONS IN THE KEPLER FIELD. I. DATABASE OF LOW-RESOLUTION SPECTRA

Author: Cat, P. De, primary, Fu, J. N., additional, Ren, A. B., additional, Yang, X. H., additional, Shi, J. R., additional, Luo, A. L., additional, Yang, M., additional, Wang, J. L., additional, Zhang, H. T., additional, Shi, H. M., additional, Zhang, W., additional, Dong, Subo, additional, Catanzaro, G., additional, Corbally, C. J., additional, Frasca, A., additional, Gray, R. O., additional, Żakowicz, J. Molenda-, additional, Uytterhoeven, K., additional, Briquet, M., additional, Bruntt, H., additional, Frandsen, S., additional, Kiss, L., additional, Kurtz, D. W., additional, Marconi, M., additional, Niemczura, E., additional, Østensen, R. H., additional, Ripepi, V., additional, Smalley, B., additional, Southworth, J., additional, Szabó, R., additional, Telting, J. H., additional, Karoff, C., additional, Aguirre, V. Silva, additional, Wu, Y., additional, Hou, Y. H., additional, Jin, G., additional, and Zhou, X. L., additional
Published: 2015
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14. The new orbital elements and properties of epsilon Persei

Author: Libich, J., Harmanec, P., Vondrak, J., Yang, S., Hadrava, P., Aerts, C.C., Cat, P. de, Koubsk�, P., Skoda, P., Slechta, M., Uytterhoeven, K., and Mathias, P.
Subjects: Astronomy
Abstract: Contains fulltext : 35168.pdf (Publisher’s version ) (Open Access) A detailed analysis of a large collection of electronic spectra from three observatories, together with radial velocities published earlier, were used to derive a new ephemeris and improved orbital elements for the ε Per binary. Observations covering a time interval of about 37 000 days (101.3 years) can be reconciled with a constant orbital period of 1406916000004. The high orbital eccentricity of 0.5550.009 was also confirmed. New spectral observations confirm that there is a periodic variation of the systemic velocity. Together with new evidence from astrometric observations (also analyzed here), they confirm the existence of a third body in the system with an orbital period of about 9600 days (26.3 years), rather than 4156 days, as reported earlier. Application of the disentangling technique to the Hα spectra with good ratios did not allow detection of spectral lines of either the secondary or tertiary components. For plausible inclinations between 30° and 90°, the observed mass function implies a mass of the secondary , if a primary mass is adopted of 13.52.0 . Attempts to detect the third body via interferometric observations should continue in spite of this first negative result.
Published: 2006

15. Multi-technique investigation of the binary fraction of A-F type candidate hybrid variable stars discovered by Kepler.

Author: Lampens, P., Frémat, Y., Vermeylen, L., Sódor, Á., Skarka, M., Cat, P. De, Bognár, Zs., Nutte, R. De, Dumortier, L., Escorza, A., Oomen, G. M., de Steene, G. Van, Kamath, D., Laverick, M., Samadi, A., Triana, S., and Lehmann, H.
Abstract: Context. Hundreds of candidate hybrid pulsators of intermediate type A–F were revealed by recent space missions. Hybrid pulsators allow us to study the full stellar interiors, where both low-order p- and high-order g-modes are simultaneously excited. The true hybrid stars must be identified since other processes, related to stellar multiplicity or rotation, might explain the presence of (some) low frequencies observed in their periodograms. Aims. We measured the radial velocities of 50 candidate δ Scuti − γ Doradus hybrid stars from the Kepler mission with the Hermes and ace spectrographs over a time span of months to years. We aim to derive the fraction of binary and multiple systems and to provide an independent and homogeneous determination of the atmospheric properties and v sin i for all targets. The long(er)-term objective is to identify the (probable) physical cause of the low frequencies. Methods. We computed one-dimensional cross-correlation functions (CCFs) in order to find the best set of parameters in terms of the number of components, spectral type(s), and v sin i for each target. Radial velocities were measured using spectrum synthesis and a two-dimensional cross-correlation technique in the case of double- and triple-lined systems. Fundamental parameters were determined by fitting (composite) synthetic spectra to the normalised median spectra corrected for the appropriate Doppler shifts. Results. We report on the analysis of 478 high-resolution Hermes and 41 ace spectra of A/F-type candidate hybrid pulsators from the Kepler field. We determined their radial velocities, projected rotational velocities, and atmospheric properties and classified our targets based on the shape of the CCFs and the temporal behaviour of the radial velocities. We derived orbital solutions for seven new systems. Three preliminary long-period orbital solutions are confirmed by a photometric time-delay analysis. Finally, we determined a global multiplicity fraction of 27% in our sample of candidate hybrid stars. [ABSTRACT FROM AUTHOR]
Published: 2018
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16. Observational results for northern and southern (candidate) gamma Doradus stars

Author: Cat, P. de, Goossens, K., Bouckaert, F., Eyer, L., Cuypers, J., Ridder, J. de, Flanders, X., Aerts, C.C., Dupret, M.A., and Grigahcene, A.
Subjects: Astronomy, Astrophysics (astro-ph), FOS: Physical sciences, Astrophysics
Abstract: We report on observational results obtained for 78 objects originally classified as bona-fide or candidate gamma Doradus stars. For the southern objects, we gathered echelle spectra with the CORALIE spectrograph attached to the Euler telescope in 1998-2003 and/or Johnson-Cousins B,V,Ic observations with the MODULAR photometer attached to the 0.5-m SAAO telescope in 1999-2000. For the northern objects, we obtained Geneva U,B,B1,B2,V,V1,G observations with the P7 photometer attached to the 1.2-m MERCATOR telescope in 2001-2004. At least 15 of our objects are binaries, of which 7 are new. For 6 binaries, we determined the orbit for the first time. At least 17 objects show profile variations and at least 12 objects are multiperiodic photometric variables. Our results allow us to upgrade 11 objects to bona-fide gamma Doradus stars and to downgrade 8 objects to constant up to the current detection limits. Mode identification is still ongoing, but so far, only l = 1 and 2 modes have been identified., Comment: 4 pages, 5 figures. To appear in: A.R. Walker & G. Bono (eds.), Proceedings of International Astrophysics Meeting 'Stellar pulsation and evolution', Memorie della Societa' Astronomica Italiana 76
Published: 2005
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17. A spectroscopic study of the beta Cephei star 12 (DD) Lacertae

Author: Desmet, M., Briquet, M., Cat, P. de, Aerts, C.C., Handler, G., Krzesinski, J., Lehmann, H., Masuda, S., Mathias, P., Mkrtichian, D.E., Telting, J.H., Uytterhoeven, K., and Yang, S.L.S.
Subjects: Astronomy, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract: Contains fulltext : 35231.pdf (Publisher’s version ) (Open Access) We present first results of a spectroscopic multisite campaign for 12 (DD) Lacertae (hereinafter 12 Lac). This star is one of the best observed beta Cephei stars. It has a large number of known oscillation frequencies but a lack of identified m-values for its detected modes. In our data set we find seven independent frequencies together with combination frequencies. In addition, two of these modes are identified: one radial mode and one prograde dipole mode.
Published: 2007

18. A spectroscopic study of southern (candidate) gamma Doradus stars. II. Detailed abundance analysis and fundamental parameters

Author: Bruntt, H., Cat, P. de, Aerts, C.C., Bruntt, H., Cat, P. de, and Aerts, C.C.
Abstract: Contains fulltext : 66076.pdf ( ) (Open Access)
Published: 2008

19. Long term photometric monitoring with the Mercator telescope. Frequencies and mode identification of variable O-B stars

Author: Cat, P. de, Briquet, M., Aerts, C.C., Goossens, K., Saesen, S., Cuypers, J., Yakut, K., Scuflaire, R., Dupret, M.A., Uytterhoeven, K., Winckel, H. van, Raskin, G., Davignon, G., Guillou, L. Le, Malderen, R. van, Reyniers, M., Acke, B., Meester, W. de, Vanautgaerden, J., Vandenbussche, B., Verhoelst, T., Waelkens, C., Deroo, P., Reyniers, K., Ausseloos, M., Broeders, E., Daszynska-Daszkiewicz, J., Debosscher, J., Ruyter, S. de, Lefever, K., Decin, G., Kolenberg, K., Mazumdar, A., Kerckhoven, C. van, Ridder, J. de, Drummond, R., Barban, C., Vanhollebeke, E., Maas, T., Decin, L., Cat, P. de, Briquet, M., Aerts, C.C., Goossens, K., Saesen, S., Cuypers, J., Yakut, K., Scuflaire, R., Dupret, M.A., Uytterhoeven, K., Winckel, H. van, Raskin, G., Davignon, G., Guillou, L. Le, Malderen, R. van, Reyniers, M., Acke, B., Meester, W. de, Vanautgaerden, J., Vandenbussche, B., Verhoelst, T., Waelkens, C., Deroo, P., Reyniers, K., Ausseloos, M., Broeders, E., Daszynska-Daszkiewicz, J., Debosscher, J., Ruyter, S. de, Lefever, K., Decin, G., Kolenberg, K., Mazumdar, A., Kerckhoven, C. van, Ridder, J. de, Drummond, R., Barban, C., Vanhollebeke, E., Maas, T., and Decin, L.
Abstract: Contains fulltext : 34555.pdf (publisher's version ) (Open Access), Aims. We selected a large sample of O-B stars that were considered as (candidate) slowly pulsating B, beta Cep, and Maia stars after the analysis of their hipparcos data. We analysed our new seven passband geneva data collected for these stars during the first three years of scientific operations of the mercator telescope. We performed a frequency analysis for 28 targets with more than 50 high-quality measurements to improve their variability classification. For the pulsating stars, we tried both to identify the modes and to search for rotationally split modes. Methods: We searched for frequencies in all the geneva passbands and colours by using two independent frequency analysis methods and we applied a 3.6 S/N-level criterion to locate the significant peaks in the periodograms. The modes were identified by applying the method of photometric amplitudes for which we calculated a large, homogeneous grid of equilibrium models to perform a pulsational stability analysis. When both the radius and the projected rotational velocity of an object are known, we determined a lower limit for the rotation frequency to estimate the expected frequency spacings in rotationally split pulsation modes. Results: We detected 61 frequencies, among which 33 are new. We classified 21 objects as pulsating variables (7 new confirmed pulsating stars, including 2 hybrid beta Cep/SPB stars), 6 as non-pulsating variables (binaries or spotted stars), and 1 as photometrically constant. All the Maia candidates were reclassified into other variability classes. We performed mode identification for the pulsating variables for the first time. The most probable l value is 0, 1, 2, and 4 for 1, 31, 9, and 5 modes, respectively, including only 4 unambiguous identifications. For 7 stars we cannot rule out that some of the observed frequencies belong to the same rotationally split mode. For 4 targets we may begin to resolve close frequency multiplets. Based on observations collected with the p7 photometer
Published: 2007

20. On the co-existence of chemically peculiar Bp stars, slowly pulsating B stars and constant B stars in the same part of the HR diagram

Author: Briquet, M., Hubrig, S., Cat, P. de, Aerts, C.C., North, P., Schöller, M., Briquet, M., Hubrig, S., Cat, P. de, Aerts, C.C., North, P., and Schöller, M.
Abstract: Contains fulltext : 35250.pdf (preprint version ) (Open Access) Contains fulltext : 35250.pdf (publisher's version ) (Open Access), Aims. In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of the H-R diagram. Methods: We carry out a comparative study between samples of confirmed and well-studied SPB stars and a sample of well-studied Bp stars with known periods and magnetic field strengths. We determine their evolutionary state using accurate HIPPARCOS parallaxes and Geneva photometry. We discuss the occurrence and strengths of magnetic fields as well as the occurrence of stellar pulsation among both groups. Further, we make a comparison of Geneva photometric variability for both kinds of stars. Results: The group of Bp stars is significantly younger than the group of SPB stars. Longitudinal magnetic fields in SPB stars are weaker than those of Bp stars, suggesting that the magnetic field strength is an important factor for B type stars to become chemically peculiar. The strongest magnetic fields appear in young Bp stars, indicating a magnetic field decay in stars at advanced ages. Rotation periods of Bp and pulsation periods of SPB stars are of the same order and the behaviour of Geneva photometric variability of some Bp stars cannot be distinguished from the variability of SPB stars, illustrating the difficulty to interpret the observed variability of the order of days for B-type stars. We consider the possibility that pulsation could be responsible for the variability among chemically peculiar stars. In particular, we show that a non-linear pulsation model is not excluded by photometry for the Bp star HD 175362.
Published: 2007

21. Mode identification of multi-periodic Slowly Pulsating B-stars: results and problems

Author: Zima, W., Cat, P. de, Aerts, C.C., Zima, W., Cat, P. de, and Aerts, C.C.
Abstract: Contains fulltext : 34487.pdf ( ) (Open Access), We report results from mode identifications (MI) for four selected multi-periodic Slowly Pulsating B-stars (SPB) using the Fourier parameter fit (FPF) method. Problems related to the pulsational nature of these objects which hamper a correct identification are discussed. For a present day status of knowledge about SPB stars we refer to De Cat (2007, this issue).
Published: 2007

22. A comparative study of B-type pulsators and non-pulsating chemically peculiar Bp stars

Author: Briquet, M., Hubrig, S., Cat, P. de, Aerts, C.C., North, P., Schöller, M., Briquet, M., Hubrig, S., Cat, P. de, Aerts, C.C., North, P., and Schöller, M.
Abstract: Contains fulltext : 34741.pdf (publisher's version ) (Open Access), We carry out a comparative study between a sample of confirmed and well-studied B-type pulsators and a sample of well-studied Bp stars with known periods and magnetic field strengths. Our study indicates that the group of Bp stars is younger than the group of SPB stars and that stars with stronger magnetic fields have much lower pulsation amplitudes.
Published: 2007

23. Activity indicators and stellar parameters of the Kepler targets An application of the ROTFIT pipeline to LAMOST-Kepler stellar spectra.

Author: Frasca, A., Molenda-Żakowicz, J., Cat, P. De, Catanzaro, G., Fu, J. N., Ren, A. B., Luo, A. L., Shi, J. R., Wu, Y., and Zhang, H. T.
Abstract: Aims. A comprehensive and homogeneous determination of stellar parameters for the stars observed by the Kepler space telescope is necessary for statistical studies of their properties. As a result of the large number of stars monitored by Kepler, the largest and more complete databases of stellar parameters published to date are multiband photometric surveys. The LAMOST-Kepler survey, whose spectra are analyzed in the present paper, was the first large spectroscopic project, which started in 2011 and aimed at filling that gap. In this work we present the results of our analysis, which is focused on selecting spectra with emission lines and chromospherically active stars by means of the spectral subtraction of inactive templates. The spectroscopic determination of the atmospheric parameters for a large number of stars is a by-product of our analysis. Methods. We have used a purposely developed version of the code ROTFIT for the determination of the stellar parameters by exploiting a wide and homogeneous collection of real star spectra, namely the Indo US library. We provide a catalog with the atmospheric parameters (Teff, log g, and [Fe/H]), radial velocity (RV), and an estimate of the projected rotation velocity (vsini). For cool stars (Teff≤ 6000 K), we also calculated the Hα and Ca ii-IRT fluxes, which are important proxies of chromospheric activity. Results. We have derived the RV and atmospheric parameters for 61 753 spectra of 51 385 stars. The average uncertainties, which we estimate from the stars observed more than once, are about 12 km s-1, 1.3%, 0.05 dex, and 0.06 dex for RV, Teff, log g, and [Fe/H], respectively, although they are larger for the spectra with a very low signal-to-noise ratio. Literature data for a few hundred stars (mainly from high-resolution spectroscopy) were used to peform quality control of our results. The final accuracy of the RV is about 14 km s-1. The accuracy of the Teff, log g, and [Fe/H] measurements is about 3.5%, 0.3 dex, and 0.2 dex, respectively. However, while the Teff values are in very good agreement with the literature, we noted some issues with the determination of [Fe/H] of metal poor stars and the tendency, for log g, to cluster around the values typical for main-sequence and red giant stars. We propose correction relations based on these comparisons and we show that this does not have a significant effect on the determination of the chromospheric fluxes. The RV distribution is asymmetric and shows an excess of stars with negative RVs that are larger at low metallicities. Despite the rather low LAMOST resolution, we were able to identify interesting and peculiar objects, such as stars with variable RV, ultrafast rotators, and emission-line objects. Based on the Hα and Ca II-IRT fluxes, we found 442 chromospherically active stars, one of which is a likely accreting object. The availability of precise rotation periods from the Kepler photometry allowed us to study the dependency of these chromospheric fluxes on the rotation rate for a very large sample of field stars. [ABSTRACT FROM AUTHOR]
Published: 2016
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24. A spectroscopic study of southern (candidate) gamma Doradus stars. I. Time series analysis

Author: Cat, P. de, Eyer, L., Cuypers, J., Aerts, C.C., Vandenbussche, B., Uytterhoeven, K., Reyniers, K., Kolenberg, K., Groenewegen, M., Raskin, G., Maas, T., Jankov, S., Cat, P. de, Eyer, L., Cuypers, J., Aerts, C.C., Vandenbussche, B., Uytterhoeven, K., Reyniers, K., Kolenberg, K., Groenewegen, M., Raskin, G., Maas, T., and Jankov, S.
Abstract: Contains fulltext : 36176.pdf (preprint version ) (Open Access) Contains fulltext : 36176.pdf (publisher's version ) (Open Access), We present the results of a spectroscopic study of 37 southern (candidate) gamma Doradus stars based on �elle spectra. The observed spectra were cross-correlated with the standard template spectrum of an F0-type star for easier detection of binary and intrinsic variations. We identified 15 objects as spectroscopic binaries, including 7 new ones, while another 3 objects are binary suspects. At least 12 objects show composite spectra. We could determine the orbital parameters for 9 binaries, of which 4 turned out to be ellipsoidal variables. For 6 binaries, we estimated the expected time-base of the orbital variations. Clear profile variations were observed for 17 objects, pointing towards stellar pulsation. For 8 of them, we have evidence that the main spectroscopic and photometric periods coincide. Our results, in combination with prior knowledge from the literature, lead to the classification of 10 objects as new bona fide gamma Doradus stars, 1 object as a new bona fide delta Scuti star, and 8 objects as constant stars. Finally, we determined the projected rotational velocity by two independent methods. The resulting v sin i values range from 3 to 135 {km s-1}. For the bona fide gamma Doradus stars, the majority has v sin i below 60 {km s-1}.
Published: 2006

25. Discovery of magnetic fields in the betaCephei star xi1 CMa and in several slowly pulsating B stars*

Author: Hubrig, S., Briquet, M., Schöller, M., Cat, P. de, Mathys, G., Aerts, C.C., Hubrig, S., Briquet, M., Schöller, M., Cat, P. de, Mathys, G., and Aerts, C.C.
Abstract: Contains fulltext : 35938.pdf ( ) (Open Access), We present the results of a magnetic survey of a sample of eight betaCephei stars and 26 slowly pulsating B (SPBs) stars with the FOcal Reducer low dispersion Spectrograph at the Very Large Telescope. A weak mean longitudinal magnetic field of the order of a few hundred Gauss is detected in the betaCephei star xi1CMa and in 13 SPB stars. The star xi1CMa becomes the third magnetic star among the betaCephei stars. Before our study, the star zetaCas was the only known magnetic SPB star. All magnetic SPB stars for which we gathered several magnetic field measurements show a field that varies in time. We do not find a relation between the evolution of the magnetic field with stellar age in our small sample. Our observations imply that betaCephei and SPB stars can no longer be considered as classes of non-magnetic pulsators, but the effect of the fields on the oscillation properties remains to be studied.
Published: 2006

26. Discovery of the New Slowly Pulsating B Star HD 163830 (B5 II/III) from MOST Space-based Photometry

Author: Aerts, C.C., Cat, P. de, Kuschnig, R., Matthews, J.M., Guenther, D.B., Moffat, A.F.J., Rucinski, S.M., Sasselov, D., Walker, G.A.H., Weiss, W.W., Aerts, C.C., Cat, P. de, Kuschnig, R., Matthews, J.M., Guenther, D.B., Moffat, A.F.J., Rucinski, S.M., Sasselov, D., Walker, G.A.H., and Weiss, W.W.
Abstract: Contains fulltext : 35940.pdf ( ) (Open Access) Contains fulltext : 35940.pdf (publisher's version ) (Closed access), We report the discovery of a new slowly pulsating B star, with the largest number of detected frequencies to date by more than a factor of 3, based on 37 days of MOST (Microvariability and Oscillations of STars) satellite guide star photometry. The star HD 163830 (V=9.3, B5 II/III) varies in 20 detected frequencies in the range 0.035-1.06 day-1 (0.4-12.3 muHz) with amplitudes from 0.7 to 7.6 mmag (with a signal-to-noise ratio from 4 to 41). Eighteen of these frequencies are consistent with low-degree, high-order nonradial g-modes of seismic models of an evolved 4.5 Msolar star. We are unable to identify one unique model due to lack of mode identifications. The lowest two frequencies may be associated with the rotation of HD 163830, but firm proof of this must await future spectroscopic data. Based on data from the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute for Aerospace Studies, and the University of British Columbia, with the assistance of the University of Vienna.
Published: 2006

27. The oscillation modes of the beta Cephei star in HD 92024 in the open cluster NGC3293

Author: Freyhammer, L.M., Hensberge, H., Sterken, C., Cat, P. de, Aerts, C.C., Goossens, K., Bouckaert, F., Eyer, L., Cuypers, J., Ridder, J. de, Flanders, X., Dupret, M.A., Grigahcene, A., Many, O., Freyhammer, L.M., Hensberge, H., Sterken, C., Cat, P. de, Aerts, C.C., Goossens, K., Bouckaert, F., Eyer, L., Cuypers, J., Ridder, J. de, Flanders, X., Dupret, M.A., Grigahcene, A., and Many, O.
Abstract: Contains fulltext : 35171.pdf (Publisher’s version ) (Closed access), The primary star of the binary HD 92024 is a prominent beta Cephei variable; three oscillation frequencies are known, it is an eclipsing binary component and has cluster membership (NGC 3293). Towards asteroseismic inferences of the star's three known oscillation frequencies, we use photometry and spectroscopy to find that f_1=5.6400 ;c d-1, f_2=7.1624 ;c d-1 and f_3=6.6584 ;c d-1 are modes of degree l=2, 4 and 2 respectively, all with m!=0. We also find that by combining pulsational information from several spectral lines, we suppress the noise and improve the mode-identification process. In conclusion, HD 92024 is a key object to be subjected to a seismic analysis. We report on observational results obtained for 78 objects originally classified as bona-fide or candidate gamma Doradus stars. For the southern objects, we gathered echelle spectra with the CORALIE spectrograph attached to the Euler telescope in 1998-2003 and/or Johnson-Cousins B,V,I_c observations with the MODULAR photometer attached to the 0.5-m SAAO telescope in 1999-2000. For the northern objects, we obtained Geneva U,B,B_1,B_2,V,V_1,G observations with the P7 photometer attached to the 1.2
Published: 2006

28. Multiperiodicity in the large-amplitude rapidly-rotating beta Cephei star HD 203664

Author: Aerts, C.C., Cat, P. de, Ridder, J. de, Winckel, H. van, Raskin, G., Davignon, G., Uytterhoeven, K., Aerts, C.C., Cat, P. de, Ridder, J. de, Winckel, H. van, Raskin, G., Davignon, G., and Uytterhoeven, K.
Abstract: Contains fulltext : 35621.pdf ( ) (Open Access), Aims.We made a seismic study of the young massive beta Cephei star HD 203664 with the goal of constraining its interior structure.Methods.Our study is based on a time series of 328 new Geneva 7-colour photometric data of the star spread over 496.8 days.Results.The data confirm the frequency of the dominant mode of the star, which we refined to f_1=6.02885 c d-1. The mode has a large amplitude of 37 mmag in V and is unambiguously identified as a dipole mode (&ea;=2) from its amplitude ratios and non-adiabatic computations. Besides f_1, we discovered two additional new frequencies in the star with amplitudes above 4sigma: f_2=6.82902 c d-1 and f_3=4.81543 c d-1, or one of their daily aliases. The amplitudes of these two modes are only between 3 and 4 mmag, which explains why they were not detected before. Their amplitude ratios are too uncertain for mode identification. Conclusions.We show that the observed oscillation spectrum of HD 203664 is compatible with standard stellar models but that we have insufficient information for asteroseismic inferences. Among the large-amplitude beta Cephei stars, HD 203664 stands out as the only one rotating at a significant fraction of its critical rotation velocity (~ 40%).
Published: 2006

29. Analysis of MERCATOR data - Part I: variable B stars

Author: Cat, P. de, Briquet, M., Aerts, C.C., Goossens, K., Saesen, S., Cuypers, J., Yakut, K., Scuflaire, R., Dupret, M.A., Cat, P. de, Briquet, M., Aerts, C.C., Goossens, K., Saesen, S., Cuypers, J., Yakut, K., Scuflaire, R., and Dupret, M.A.
Abstract: Contains fulltext : 36148.pdf ( ) (Open Access), We re-classified 31 variable B stars which were observed more than 50 times in the Geneva photometric system with the p7 photometer attached to the MERCATOR telescope (La Palma) during its first 3 years of scientific observations. HD 89688 is a possible beta Cephei/slowly pulsating B star hybrid and the main mode of the COROT target HD 180642 shows non-linear effects. The Maia candidates are re-classified as either ellipsoidal variables or spotted stars. Although the mode identification is still ongoing, all the well-identified modes so far have l <= 2.
Published: 2006

30. Observational results for northern and southern (candidate) gamma Doradus stars

Author: Cat, P. de, Goossens, K., Bouckaert, F., Eyer, L., Cuypers, J., Ridder, J. de, Flanders, X., Aerts, C.C., Dupret, M.A., Grigahcene, A., Cat, P. de, Goossens, K., Bouckaert, F., Eyer, L., Cuypers, J., Ridder, J. de, Flanders, X., Aerts, C.C., Dupret, M.A., and Grigahcene, A.
Abstract: Contains fulltext : 35585.pdf ( ) (Open Access), We report on observational results obtained for 78 objects originally classified as bona-fide or candidate gamma Doradus stars. For the southern objects, we gathered echelle spectra with the CORALIE spectrograph attached to the Euler telescope in 1998-2003 and/or Johnson-Cousins B,V,I_c observations with the MODULAR photometer attached to the 0.5-m SAAO telescope in 1999-2000. For the northern objects, we obtained Geneva U,B,B_1,B_2,V,V_1,G observations with the P7 photometer attached to the 1.2-m Mercator telescope in 2001-2004. At least 15 of our objects are binaries, of which 7 are new. For 6 binaries, we determined the orbit for the first time. At least 17 objects show profile variations and at least 12 objects are multiperiodic photometric variables. Our results allow us to upgrade 11 objects to bona-fide gamma Doradus stars and to downgrade 8 objects to constant up to the current detection limits. Mode identification is still ongoing, but so far, only ? = 1 and 2 modes have been identified.
Published: 2006

31. A study of bright southern slowly pulsating B stars. III. Mode identification for singly-periodic targets in spectroscopy

Author: Cat, P. de, Briquet, M., Daszynska-Daszkiewicz, J., Dupret, M.A., Ridder, J. de, Scuflaire, R., Aerts, C.C., Cat, P. de, Briquet, M., Daszynska-Daszkiewicz, J., Dupret, M.A., Ridder, J. de, Scuflaire, R., and Aerts, C.C.
Abstract: Contains fulltext : 33307.pdf (publisher's version ) (Open Access), We present the results of the mode identification for a sample of 7 bright southern slowly pulsating B stars showing one pulsation frequency in the lambdalambda 413 nm Si II profiles. We combined the results from (1) the method of photometric amplitudes; (2) the moment method; and (3) the amplitude and phase variation across the profile to search for the l and m values of the modes best fitting the data. It is the first time that the applicability of these techniques is tested to a sample of main-sequence g-mode pulsators. Combining the moment method with the amplitude and phase variations across the observed line profile gives an improvement in spectroscopic identification of low degree l g-mode pulsations. Using the variations of the higher order even moments < v4> and < v6> of the moment method solutions can also help. For HD 181558, HD 24587, HD 140873 and HD 177863, the photometric and spectroscopic results are compatible and point towards (l,m) = (1, +1) sectoral modes. For HD 215573, HD 53921 and HD 92287, the results are inconclusive. Our proposed methodology for mode identification is also applicable to gamma Doradus stars. Based on observations collected with the CAT Telescope of the European Southern Observatory and with the Swiss Photometric Telescope of the Geneva Observatory, both situated at La Silla in Chile.
Published: 2005

32. A 4-Mb BAC/PAC contig and complete genomic structure of the GPC5/GPC6 gene cluster on chromosome 13q32

Author: Veugelers, M., Cat, B. De, Delande, N., Esselens, C., Bonk, I., Vermeesch, J., Marynen, P., Fryns, J. P., and David, G.
Published: 2001
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33. Towards a unified analysis of French floating quantifiers

Author: Cat, Cécile De
Abstract: In French, a quantifier can appear in various positions outside of the NP it quantifies over, whether this NP is the subject or the (direct or indirect) object of the sentence. This phenomenon, often referred to as floating, has been investigated since the early stages of the generative framework, and several analyses have been proposed to account for both the quantifier subject and the quantifier object in a unified way. However, to my knowledge, none of them has succeeded in providing such a unified account without recourse to non-explanatory restrictions. The main aim of this paper is to propose an analysis that does not require any such restrictions. The focus will be on anaphoric quantifiers (i.e. quantifiers that have to be linked to some other argument position in order to be interpretable), the analysis of which will be shown to extend straightforwardly to pronominal and adverbial quantifiers, according to the principles of Government and Binding theory.The study of floating quantifiers raises the broader question of how to account for locality requirements in a satisfactory way. Basically, there are two possible ways to account for the restrictions on the distribution of floating quantifiers: either they flow from derivational restrictions, or they are subject to representational restrictions. I will argue in favour of the latter.The analysis proposed here is essentially syntactic. However, reference will be made to the semantic interpretation of various structures: the position occupied by the floating quantifier at S-structure will be shown to constrain its interpretation. The semantics of floating quantifiers will however not be investigated beyond this.
Published: 2000

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

Author: Van Leeuwen, F. Vallenari, A. Jordi, C. Lindegren, L. Bastian, U. Prusti, T. De Bruijne, J.H.J. Brown, A.G.A. Babusiaux, C. Bailer-Jones, C.A.L. Biermann, M. Evans, D.W. Eyer, L. Jansen, F. Klioner, S.A. Lammers, U. Luri, X. Mignard, F. Panem, C. Pourbaix, D. Randich, S. Sartoretti, P. Siddiqui, H.I. Soubiran, C. Valette, V. Walton, N.A. Aerts, C. Arenou, F. Cropper, M. Drimmel, R. Høg, E. Katz, D. Lattanzi, M.G. O'Mullane, W. Grebel, E.K. Holland, A.D. Huc, C. Passot, X. Perryman, M. Bramante, L. Cacciari, C. Castañeda, J. Chaoul, L. Cheek, N. De Angeli, F. Fabricius, C. Guerra, R. Hernández, J. Jean-Antoine-Piccolo, A. Masana, E. Messineo, R. Mowlavi, N. Nienartowicz, K. Ordóñez-Blanco, D. Panuzzo, P. Portell, J. Richards, P.J. Riello, M. Seabroke, G.M. Tanga, P. Thévenin, F. Torra, J. Els, S.G. Gracia-Abril, G. Comoretto, G. Garcia-Reinaldos, M. Lock, T. Mercier, E. Altmann, M. Andrae, R. Astraatmadja, T.L. Bellas-Velidis, I. Benson, K. Berthier, J. Blomme, R. Busso, G. Carry, B. Cellino, A. Clementini, G. Cowell, S. Creevey, O. Cuypers, J. Davidson, M. De Ridder, J. De Torres, A. Delchambre, L. Dell'oro, A. Ducourant, C. Frémat, Y. García-Torres, M. Gosset, E. Halbwachs, J.-L. Hambly, N.C. Harrison, D.L. Hauser, M. Hestroffer, D. Hodgkin, S.T. Huckle, H.E. Hutton, A. Jasniewicz, G. Jordan, S. Kontizas, M. Korn, A.J. Lanzafame, A.C. Manteiga, M. Moitinho, A. Muinonen, K. Osinde, J. Pancino, E. Pauwels, T. Petit, J.-M. Recio-Blanco, A. Robin, A.C. Sarro, L.M. Siopis, C. Smith, M. Smith, K.W. Sozzetti, A. Thuillot, W. Van Reeven, W. Viala, Y. Abbas, U. Abreu Aramburu, A. Accart, S. Aguado, J.J. Allan, P.M. Allasia, W. Altavilla, G. Álvarez, M.A. Alves, J. Anderson, R.I. Andrei, A.H. Anglada Varela, E. Antiche, E. Antoja, T. Antón, S. Arcay, B. Bach, N. Baker, S.G. Balaguer-Núñez, L. Barache, C. Barata, C. Barbier, A. Barblan, F. Navascués, B.Y.D. Barros, M. Barstow, M.A. Becciani, U. Bellazzini, M. Bello García, A. Belokurov, V. Bendjoya, P. Berihuete, A. Bianchi, L. Bienaymé, O. Billebaud, F. Blagorodnova, N. Blanco-Cuaresma, S. Boch, T. Bombrun, A. Borrachero, R. Bouquillon, S. Bourda, G. Bouy, H. Bragaglia, A. Breddels, M.A. Brouillet, N. Brüsemeister, T. Bucciarelli, B. Burgess, P. Burgon, R. Burlacu, A. Busonero, D. Buzzi, R. Caffau, E. Cambras, J. Campbell, H. Cancelliere, R. Cantat-Gaudin, T. Carlucci, T. Carrasco, J.M. Castellani, M. Charlot, P. Charnas, J. Chiavassa, A. Clotet, M. Cocozza, G. Collins, R.S. Costigan, G. Crifo, F. Cross, N.J.G. Crosta, M. Crowley, C. Dafonte, C. Damerdji, Y. Dapergolas, A. David, P. David, M. De Cat, P. De Felice, F. De Laverny, P. De Luise, F. De March, R. De Martino, D. De Souza, R. Debosscher, J. Del Pozo, E. Delbo, M. Delgado, A. Delgado, H.E. Di Matteo, P. Diakite, S. Distefano, E. Dolding, C. Dos Anjos, S. Drazinos, P. Durán, J. Dzigan, Y. Edvardsson, B. Enke, H. Evans, N.W. Eynard Bontemps, G. Fabre, C. Fabrizio, M. Faigler, S. Falcão, A.J. Farràs Casas, M. Federici, L. Fedorets, G. Fernández-Hernández, J. Fernique, P. Fienga, A. Figueras, F. Filippi, F. Findeisen, K. Fonti, A. Fouesneau, M. Fraile, E. Fraser, M. Fuchs, J. Gai, M. Galleti, S. Galluccio, L. Garabato, D. García-Sedano, F. Garofalo, A. Garralda, N. Gavras, P. Gerssen, J. Geyer, R. Gilmore, G. Girona, S. Giuffrida, G. Gomes, M. González-Marcos, A. González-Núñez, J. González-Vidal, J.J. Granvik, M. Guerrier, A. Guillout, P. Guiraud, J. Gúrpide, A. Gutiérrez-Sánchez, R. Guy, L.P. Haigron, R. Hatzidimitriou, D. Haywood, M. Heiter, U. Helmi, A. Hobbs, D. Hofmann, W. Holl, B. Holland, G. Hunt, J.A.S. Hypki, A. Icardi, V. Irwin, M. Jevardat De Fombelle, G. Jofré, P. Jonker, P.G. Jorissen, A. Julbe, F. Karampelas, A. Kochoska, A. Kohley, R. Kolenberg, K. Kontizas, E. Koposov, S.E. Kordopatis, G. Koubsky, P. Krone-Martins, A. Kudryashova, M. Kull, I. Bachchan, R.K. Lacoste-Seris, F. Lanza, A.F. Lavigne, J.-B. Le Poncin-Lafitte, C. Lebreton, Y. Lebzelter, T. Leccia, S. Leclerc, N. Lecoeur-Taibi, I. Lemaitre, V. Lenhardt, H. Leroux, F. Liao, S. Licata, E. Lindstrøm, H.E.P. Lister, T.A. Livanou, E. Lobel, A. Löffler, W. López, M. Lorenz, D. MacDonald, I. Magalhães Fernandes, T. Managau, S. Mann, R.G. Mantelet, G. Marchal, O. Marchant, J.M. Marconi, M. Marinoni, S. Marrese, P.M. Marschalkó, G. Marshall, D.J. Martín-Fleitas, J.M. Martino, M. Mary, N. Matijevič, G. Mazeh, T. McMillan, P.J. Messina, S. Michalik, D. Millar, N.R. Miranda, B.M.H. Molina, D. Molinaro, R. Molinaro, M. Molnár, L. Moniez, M. Montegriffo, P. Mor, R. Mora, A. Morbidelli, R. Morel, T. Morgenthaler, S. Morris, D. Mulone, A.F. Muraveva, T. Musella, I. Narbonne, J. Nelemans, G. Nicastro, L. Noval, L. Ordénovic, C. Ordieres-Meré, J. Osborne, P. Pagani, C. Pagano, I. Pailler, F. Palacin, H. Palaversa, L. Parsons, P. Pecoraro, M. Pedrosa, R. Pentikäinen, H. Pichon, B. Piersimoni, A.M. Pineau, F.-X. Plachy, E. Plum, G. Poujoulet, E. Prša, A. Pulone, L. Ragaini, S. Rago, S. Rambaux, N. Ramos-Lerate, M. Ranalli, P. Rauw, G. Read, A. Regibo, S. Reylé, C. Ribeiro, R.A. Rimoldini, L. Ripepi, V. Riva, A. Rixon, G. Roelens, M. Romero-Gómez, M. Rowell, N. Royer, F. Ruiz-Dern, L. Sadowski, G. Sagristà Sellés, T. Sahlmann, J. Salgado, J. Salguero, E. Sarasso, M. Savietto, H. Schultheis, M. Sciacca, E. Segol, M. Segovia, J.C. Segransan, D. Shih, I.-C. Smareglia, R. Smart, R.L. Solano, E. Solitro, F. Sordo, R. Soria Nieto, S. Souchay, J. Spagna, A. Spoto, F. Stampa, U. Steele, I.A. Steidelmüller, H. Stephenson, C.A. Stoev, H. Suess, F.F. Süveges, M. Surdej, J. Szabados, L. Szegedi-Elek, E. Tapiador, D. Taris, F. Tauran, G. Taylor, M.B. Teixeira, R. Terrett, D. Tingley, B. Trager, S.C. Turon, C. Ulla, A. Utrilla, E. Valentini, G. Van Elteren, A. Van Hemelryck, E. Vanleeuwen, M. Varadi, M. Vecchiato, A. Veljanoski, J. Via, T. Vicente, D. Vogt, S. Voss, H. Votruba, V. Voutsinas, S. Walmsley, G. Weiler, M. Weingrill, K. Wevers, T. Wyrzykowski, A. Yoldas, A. Zerjal, M. Zucker, S. Zurbach, C. Zwitter, T. Alecu, A. Allen, M. Allende Prieto, C. Amorim, A. Anglada-Escudé, G. Arsenijevic, V. Azaz, S. Balm, P. Beck, M. Bernstein, H.-H. Bigot, L. Bijaoui, A. Blasco, C. Bonfigli, M. Bono, G. Boudreault, S. Bressan, A. Brown, S. Brunet, P.-M. Bunclark, P. Buonanno, R. Butkevich, A.G. Carret, C. Carrion, C. Chemin, L. Chéreau, F. Corcione, L. Darmigny, E. De Boer, K.S. De Teodoro, P. De Zeeuw, P.T. Delle Luche, C. Domingues, C.D. Dubath, P. Fodor, F. Frézouls, B. Fries, A. Fustes, D. Fyfe, D. Gallardo, E. Gallegos, J. Gardiol, D. Gebran, M. Gomboc, A. Gómez, A. Grux, E. Gueguen, A. Heyrovsky, A. Hoar, J. Iannicola, G. Isasi Parache, Y. Janotto, A.-M. Joliet, E. Jonckheere, A. Keil, R. Kim, D.-W. Klagyivik, P. Klar, J. Knude, J. Kochukhov, O. Kolka, I. Kos, J. Kutka, A. Lainey, V. Lebouquin, D. Liu, C. Loreggia, D. Makarov, V.V. Marseille, M.G. Martayan, C. Martinez-Rubi, O. Massart, B. Meynadier, F. Mignot, S. Munari, U. Nguyen, A.-T. Nordlander, T. O'Flaherty, K.S. Ocvirk, P. Olias Sanz, A. Ortiz, P. Osorio, J. Oszkiewicz, D. Ouzounis, A. Palmer, M. Park, P. Pasquato, E. Peltzer, C. Peralta, J. Péturaud, F. Pieniluoma, T. Pigozzi, E. Poels, J. Prat, G. Prod'homme, T. Raison, F. Rebordao, J.M. Risquez, D. Rocca-Volmerange, B. Rosen, S. Ruiz-Fuertes, M.I. Russo, F. Sembay, S. Serraller Vizcaino, I. Short, A. Siebert, A. Silva, H. Sinachopoulos, D. Slezak, E. Soffel, M. Sosnowska, D. StraiÅ Ys, V. Ter Linden, M. Terrell, D. Theil, S. Tiede, C. Troisi, L. Tsalmantza, P. Tur, D. Vaccari, M. Vachier, F. Valles, P. Van Hamme, W. Veltz, L. Virtanen, J. Wallut, J.-M. Wichmann, R. Wilkinson, M.I. Ziaeepour, H. Zschocke, S.
Abstract: Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs. © 2017 ESO.

35. ON THE METALLICITIES OF KEPLER STARS.

Author: Dong, Subo, Zheng, Zheng, Zhu, Zhaohuan, Cat, P. De, Fu, J. N., Yang, X. H., Zhang, Haotong, Jin, Ge, and Zhang, Yong
Published: 2014
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35 results on '"Cat, P. de"'

1. Spectroscopic mode identification of γ Doradus stars

2. Low-frequency gravity waves in blue supergiants revealed by high-precision space photometry

3. K2 photometry and HERMES spectroscopy of the blue supergiant ρ Leo: rotational wind modulation and low-frequency waves★

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

5. The Gaia mission

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

7. Analysis of MERCATOR data - Part II: variable A & F stars is of MERCATOR data - Part I: variable B stars

8. Pulsation versus metallicism in Am stars as revealed by LAMOST and WASP

9. Kepler observations of the variability in B-type stars

10. Spectroscopic survey of Kepler stars. I. HERMES/Mercator observations of A- and F-type stars

11. Lamost observations in the kepler field. I. Database of low-resolution spectra*

12. LAMOST OBSERVATIONS IN THEKEPLERFIELD: SPECTRAL CLASSIFICATION WITH THE MKCLASS CODE

13. LAMOST OBSERVATIONS IN THE KEPLER FIELD. I. DATABASE OF LOW-RESOLUTION SPECTRA

14. The new orbital elements and properties of epsilon Persei

15. Multi-technique investigation of the binary fraction of A-F type candidate hybrid variable stars discovered by Kepler.

16. Observational results for northern and southern (candidate) gamma Doradus stars

17. A spectroscopic study of the beta Cephei star 12 (DD) Lacertae

18. A spectroscopic study of southern (candidate) gamma Doradus stars. II. Detailed abundance analysis and fundamental parameters

19. Long term photometric monitoring with the Mercator telescope. Frequencies and mode identification of variable O-B stars

20. On the co-existence of chemically peculiar Bp stars, slowly pulsating B stars and constant B stars in the same part of the HR diagram

21. Mode identification of multi-periodic Slowly Pulsating B-stars: results and problems

22. A comparative study of B-type pulsators and non-pulsating chemically peculiar Bp stars

23. Activity indicators and stellar parameters of the Kepler targets An application of the ROTFIT pipeline to LAMOST-Kepler stellar spectra.

24. A spectroscopic study of southern (candidate) gamma Doradus stars. I. Time series analysis

25. Discovery of magnetic fields in the betaCephei star xi1 CMa and in several slowly pulsating B stars*

26. Discovery of the New Slowly Pulsating B Star HD 163830 (B5 II/III) from MOST Space-based Photometry

27. The oscillation modes of the beta Cephei star in HD 92024 in the open cluster NGC3293

28. Multiperiodicity in the large-amplitude rapidly-rotating beta Cephei star HD 203664

29. Analysis of MERCATOR data - Part I: variable B stars

30. Observational results for northern and southern (candidate) gamma Doradus stars

31. A study of bright southern slowly pulsating B stars. III. Mode identification for singly-periodic targets in spectroscopy

32. A 4-Mb BAC/PAC contig and complete genomic structure of the GPC5/GPC6 gene cluster on chromosome 13q32

33. Towards a unified analysis of French floating quantifiers

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

35. ON THE METALLICITIES OF KEPLER STARS.

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