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Author name code: eriksson
ADS astronomy entries on 2022-09-14
author:"Eriksson, Kjell" 

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Title: Dynamic atmospheres and winds of cool luminous
    giants. II. Gradual Fe enrichment of wind-driving silicate grains
Authors: Höfner, S.; Bladh, S.; Aringer, B.; Eriksson, K.
2022A&A...657A.109H    Altcode: 2021arXiv211015899H
  Context. The winds observed around asymptotic giant branch (AGB)
  stars are generally attributed to radiation pressure on dust
  formed in the extended dynamical atmospheres of these long-period
  variables. The composition of wind-driving grains is affected by a
  feedback between their optical properties and the resulting heating
  due to stellar radiation. <BR /> Aims: We explore the gradual Fe
  enrichment of wind-driving silicate grains in M-type AGB stars to
  derive typical values for Fe/Mg and to test the effects on wind
  properties and synthetic spectra. <BR /> Methods: We present new
  radiation-hydrodynamical DARWIN models that allow for the growth of
  silicate grains with a variable Fe/Mg ratio and predict mass-loss
  rates, wind velocities, and grain properties. Synthetic spectra and
  other observables are computed a posteriori with the COMA code. <BR
  /> Results: The self-regulating feedback between grain composition
  and radiative heating, in combination with quickly falling densities
  in the stellar wind, leads to low values of Fe/Mg, typically a few
  percent. Nevertheless, the new models show distinct silicate features
  around 10 and 18 microns. Fe enrichment affects visual and near-IR
  photometry moderately, and the new DARWIN models agree well with
  observations in (J − K) versus (V − K) and Spitzer color-color
  diagrams. The enrichment of the silicate dust with Fe is a secondary
  process, taking place in the stellar wind on the surface of large
  Fe-free grains that have initiated the outflow. Therefore, the mass-loss
  rates are basically unaffected, while the wind velocities tend to be
  slightly higher than in corresponding models with Fe-free silicate
  dust. <BR /> Conclusions: The gradual Fe enrichment of silicate grains
  in the inner wind region should produce signatures observable in mid-IR
  spectro-interferometrical measurements. Mass-loss rates derived from
  existing DARWIN models, based on Fe-free silicates, can be applied to
  stellar evolution models since the mass-loss rates are not significantly
  affected by the inclusion of Fe in the silicate grains.

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Title: Gaia Data Release 2. The kinematics of globular clusters and
    dwarf galaxies around the Milky Way (Corrigendum)
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
   P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
   Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
   M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
   J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
   J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
   F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
   C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
   Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
   Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
   L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
   Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
   P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
   F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
   D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
   K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
   Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
   M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
   Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
   García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
   Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
   Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
   Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
   Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
   R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
   Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
   Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
   P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
   S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
   Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
   T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
   S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
   Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
   Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
   C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
   P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
   Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
   Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
   E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
   Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
   M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
   Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
   Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti,
   S.; Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.;
   Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore,
   G.; Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.;
   Gueguen, A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.;
   Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter,
   U.; Heu, J.; Hilger, T.; Hofmann, W.; Holland, G.; Huckle, H. E.;
   Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker,
   P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar,
   J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas,
   E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky,
   P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Matijevič, G.; Mazeh, T.; Messina,
   S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
   L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
   Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro,
   L.; Noval, L.; O'Mullane, W.; Ordénovic, C.; Ordóñez-Blanco,
   D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
   Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.; Pineau,
   F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša, A.;
   Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.;
   Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.;
   Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
   F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann,
   J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso,
   M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia,
   J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart,
   R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto,
   S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.;
   Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
   J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
   G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
   Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.;
   Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.;
   van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.;
   Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss,
   H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.;
   Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
   H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2020A&A...642C...1G    Altcode:
  No abstract at ADS

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Title: Gaia Data Release 2. Kinematics of globular clusters and
    dwarf galaxies around the Milky Way (Corrigendum)
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
   P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
   Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
   M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
   J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
   J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
   F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
   C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
   Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
   Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
   L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
   Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
   P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
   F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
   D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
   K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
   Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
   M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
   Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
   García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
   Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
   Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
   Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
   Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
   R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
   Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
   Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
   P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
   S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
   Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
   T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
   S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
   Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
   Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
   C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
   P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
   Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
   Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
   E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
   Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
   M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
   Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
   Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti,
   S.; Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.;
   Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore,
   G.; Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.;
   Gueguen, A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.;
   Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter,
   U.; Heu, J.; Hilger, T.; Hofmann, W.; Holland, G.; Huckle, H. E.;
   Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker,
   P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar,
   J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas,
   E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky,
   P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Matijevič, G.; Mazeh, T.; Messina,
   S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
   L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
   Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro,
   L.; Noval, L.; O'Mullane, W.; Ordénovic, C.; Ordóñez-Blanco,
   D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.; Palacin, H.;
   Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.; Pineau,
   F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša, A.;
   Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.;
   Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.;
   Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer,
   F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann,
   J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso,
   M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.; Segovia,
   J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart,
   R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto,
   S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.;
   Steidelmüller, H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
   J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
   G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
   Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.;
   Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.;
   van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.;
   Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss,
   H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.;
   Wevems, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
   H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2020A&A...637C...3G    Altcode:
  No abstract at ADS

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Title: Precision Monitoring of Cool Evolved Stars: Constraining
    Effects of Convection and Pulsation
Authors: Wittkowski, M.; Bladh, S.; Chiavassa, A.; de Wit, W. -J.;
   Eriksson, K.; Freytag, B.; Haubois, X.; Höfner, S.; Kravchenko, K.;
   Paladini, C.; Paumard, T.; Rau, G.; Wood, P. R.
2019Msngr.178...34W    Altcode:
  Mass loss from cool evolved stars is an important ingredient of
  the cosmic matter cycle, enriching the Universe with newly formed
  elements and dust. However, physical processes that are not considered
  in current models represent uncertainties in our general understanding
  of mass loss. Time-series of interferometric data provide the strongest
  tests of dynamical processes in the atmospheres of these stars. Here,
  we present a pilot study of such measurements obtained with the GRAVITY
  instrument on the Very Large Telescope Interferometer.

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Title: A DARWIN C-star model grid with new dust opacities
Authors: Eriksson, Kjell; Höfner, Susanne; Aringer, Bernhard
2019IAUS..343..391E    Altcode:
  We have improved the treatment of dust opacity from the small-particle
  limit approximation to size-dependent which leads to models with
  smaller grains, lower dust-to-gas ratios, but about the same mass-loss
  rates and outflow velocities. The K-magnitudes get brighter, whereas
  the V-magnitudes can be either brighter or dimmer depending on the
  wind properties.

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Title: Constraining the thermally pulsing asymptotic giant branch
    phase with resolved stellar populations in the Small Magellanic Cloud
Authors: Pastorelli, Giada; Marigo, Paola; Girardi, Léo; Chen,
   Yang; Rubele, Stefano; Trabucchi, Michele; Aringer, Bernhard; Bladh,
   Sara; Bressan, Alessandro; Montalbán, Josefina; Boyer, Martha L.;
   Dalcanton, Julianne J.; Eriksson, Kjell; Groenewegen, Martin A. T.;
   Höfner, Susanne; Lebzelter, Thomas; Nanni, Ambra; Rosenfield, Philip;
   Wood, Peter R.; Cioni, Maria-Rosa L.
2019MNRAS.485.5666P    Altcode: 2019MNRAS.tmp..738P; 2019arXiv190304499P
  The thermally pulsing asymptotic giant branch (TP-AGB) experienced by
  low- and intermediate-mass stars is one of the most uncertain phases
  of stellar evolution and the models need to be calibrated with the aid
  of observations. To this purpose, we couple high-quality observations
  of resolved stars in the Small Magellanic Cloud (SMC) with detailed
  stellar population synthesis simulations computed with the TRILEGAL
  code. The strength of our approach relies on the detailed spatially
  resolved star formation history of the SMC, derived from the deep
  near-infrared photometry of the VISTA survey of the Magellanic Clouds,
  as well as on the capability to quickly and accurately explore a
  wide variety of parameters and effects with the COLIBRI code for the
  TP-AGB evolution. Adopting a well-characterized set of observations -
  star counts and luminosity functions - we set up a calibration cycle
  along which we iteratively change a few key parameters of the TP-AGB
  models until we eventually reach a good fit to the observations. Our
  work leads to identify two best-fitting models that mainly differ in
  the efficiencies of the third dredge-up and mass-loss in TP-AGB stars
  with initial masses larger than about 3 M<SUB>⊙</SUB>. On the basis
  of these calibrated models, we provide a full characterization of the
  TP-AGB stellar population in the SMC in terms of stellar parameters
  (initial masses, C/O ratios, carbon excess, mass-loss rates). Extensive
  tables of isochrones including these improved models are publicly
  available.

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Title: VizieR Online Data Catalog: Gaia DR2. Variable stars in CMD
    (Gaia Collaboration+, 2019)
Authors: Gaia Collaboration; Eyer, L.; Rimoldini, L.; Audard, M.;
   Anderson, R. I.; Nienartowicz, K.; Glass, F.; Marchal, O.; Grenon, M.;
   Mowlavi, N.; Holl, B.; Clementini, G.; Aerts, C.; Mazeh, T.; Evans,
   D. W.; Szabados, L.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de
   Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann,
   M.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren,
   L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.;
   Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; van Leeuwen, F.;
   Walton, N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.;
   Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castaneda,
   J.; Chaoul, L.; Cheek, N.; de Angeli, F.; Fabricius, C.; Guerra,
   R.; Masana, E.; Messineo, R.; Panuzzo, P.; Portell, J.; Riello, M.;
   Seabroke, G. M.; Tanga, P.; Thevenin, F.; Gracia-Abril, G.; Comoretto,
   G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
   Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess,
   P.; Busso, G.; Carry, B.; Cellino, A.; Clotet, M.; Creevey, O.;
   Davidson, M.; de Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant,
   C.; Fernandez-Hernandez, J.; Fouesneau, M.; Fremat, Y.; Galluccio, L.;
   Garcia-Torres, M.; Gonzalez-Nunez, J.; Gonzalez-Vidal, J. J.; Gosset,
   E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.;
   Hernandez, J.; Hestroer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz,
   G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins,
   A.; Lanzafame, A. C.; Lebzelter, T.; Loeer, W.; Manteiga, M.; Marrese,
   P. M.; Martin-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
   Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco,
   A.; Richards, P. J.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith,
   M.; Sozzetti, A.; Sueveges, M.; Torra, J.; van Reeven, W.; Abbas,
   U.; Abreu Aramburu, A.; Accart, S.; Altavilla, G.; Alvarez, M. A.;
   Alvarez, R.; Alves, J.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.;
   Antoja, T.; Arcay, B.; Astraatmadja, T. L.; Bach, N.; Baker, S. G.;
   Balaguer-Nunez, L.; Balm, P.; Barache, C.; Barata, C.; Barbato, D.;
   Barblan, F.; Barklem, P. S.; Barrado, D.; Barros, M.; Barstow, M. A.;
   Bartholome Munoz, S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.;
   Berihuete, A.; Bertone, S.; Bianchi, L.; Bienayme, O.; Blanco-Cuaresma,
   S.; Boch, T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.;
   Bouquillon, S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels,
   M. A.; Bressan, A.; Brouillet, N.; Bruesemeister, T.; Brugaletta,
   E.; Bucciarelli, B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.;
   Buzzi, R.; Caau, E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin,
   T.; Carballo, R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.;
   Castellani, M.; Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa,
   A.; Cocozza, G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.;
   Crowley, C.; Cuypersy, J.; Dafonte, C.; Damerdji, Y.; Dapergolas,
   A.; David, P.; David, M.; de Laverny, P.; de Luise, F.; de March,
   R.; de Martino, D.; de Souza, R.; de Torres, A.; Debosscher, J.;
   Del Pozo, E.; Delbo, M.; Delgado, A.; Delgado, H. E.; Diakite, S.;
   Diener, C.; Distefano, E.; Dolding, C.; Drazinos, P.; Duran, J.;
   Edvardsson, B.; Enke, H.; Eriksson, K.; Esquej, P.; Eynard Bontemps,
   G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcao, A. J.; Farras Casas,
   M.; Federici, L.; Fedorets, G.; Fernique, P.; Figueras, F.; Filippi,
   F.; Findeisen, K.; Fonti, A.; Fraile, E.; Fraser, M.; Frezouls, B.;
   Gai, M.; Galleti, S.; Garabato, D.; Garcia-Sedano, F.; Garofalo, A.;
   Garralda, N.; Gavel, A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe,
   P.; Gilmore, G.; Girona, S.; Giurida, G.; Gomes, M.; Granvik, M.;
   Gueguen, A.; Guerrier, A.; Guiraud, J.; Gutierrez-Sanchez, R.; Haigron,
   R.; Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi,
   A.; Heu, J.; Hilger, T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle,
   H. E.; Hypki, A.; Icardi, V.; Janssen, K.; Jevardat de Fombelle,
   G.; Jonker, P. G.; Juhasz, A. L.; Julbe, F.; Karampelas, A.; Kewley,
   A.; Klar, J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.;
   Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.;
   Koubsky, P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.;
   Le Fustec, Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.;
   Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.;
   Licata, E.; Lindstrom, H. E. P.; Lister, T. A.; Livanou, E.; Lobel,
   A.; Lopez, M.; Lorenz, D.; Managau, S.; Mann, R. G.; Mantelet, G.;
   Marchant, J. M.; Marconi, M.; Marinoni, S.; Marschalko, G.; Marshall,
   D. J.; Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevic, G.;
   McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
   D.; Molinaro, R.; Molnar, L.; Montegrio, P.; Mor, R.; Morbidelli, R.;
   Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Muraveva, T.;
   Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.;
   Ordenovic, C.; Ordonez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano,
   I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.;
   Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio,
   E.; Poujoulet, E.; Prsa, A.; Pulone, L.; Racero, E.; Ragaini, S.;
   Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Reyle, C.; Riclet, F.;
   Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers, T.; Roelens,
   M.; Romero-Gomez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski,
   G.; Sagrista Selles, T.; Sahlmann, J.; Salgado, J.; Salguero, E.;
   Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.; Schultheis, M.;
   Sciacca, E.; Segol, M.; Segovia, J. C.; Segransan, D.; Shih, I. -C.;
   Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.; Solano, E.;
   Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.;
   Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmueller, H.; Stephenson,
   C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szegedi-Elek, E.; Tapiador,
   D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.;
   Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon,
   C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.;
   Valette, V.; van Elteren, A.; van Hemelryck, E.; van Leeuwen, M.;
   Vaschetto, M.; Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente,
   D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.;
   Walmsley, G.; Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, L.;
   Yoldas, A.; Zerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.;
   Zucker, S.; Zurbach, C.; Zwitter, T.
2019yCat..36230110G    Altcode:
  Time series in the G, BP, and RP bands of the selected field-of-view
  transits for 224 sources that are not published in Gaia DR2, but
  are plotted in Fig. 11. An animated version of Fig. 11 is provided
  online and at https://www.cosmos.esa.int/web/gaia/gaiadr2_cu7. <P />(2
  data files).

---------------------------------------------------------
Title: Gaia Data Release 2. Variable stars in the colour-absolute
    magnitude diagram
Authors: Gaia Collaboration; Eyer, L.; Rimoldini, L.; Audard, M.;
   Anderson, R. I.; Nienartowicz, K.; Glass, F.; Marchal, O.; Grenon,
   M.; Mowlavi, N.; Holl, B.; Clementini, G.; Aerts, C.; Mazeh, T.;
   Evans, D. W.; Szabados, L.; Brown, A. G. A.; Vallenari, A.; Prusti,
   T.; de Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.;
   Biermann, M.; Jansen, F.; Jordi, C.; Klioner, S. A.; Lammers, U.;
   Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich,
   S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; van Leeuwen, F.;
   Walton, N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.;
   Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda,
   J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra,
   R.; Masana, E.; Messineo, R.; Panuzzo, P.; Portell, J.; Riello, M.;
   Seabroke, G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
   G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
   Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess,
   P.; Busso, G.; Carry, B.; Cellino, A.; Clotet, M.; Creevey, O.;
   Davidson, M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant,
   C.; Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio,
   L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
   J. -M.; Recio-Blanco, A.; Richards, P. J.; Robin, A. C.; Sarro,
   L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.;
   van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Altavilla,
   G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Andrei, A. H.; Anglada
   Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
   Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barache,
   C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado,
   D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz, S.; Bassilana,
   J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bertone, S.;
   Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.;
   Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon, S.; Bourda, G.;
   Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan, A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
   Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
   Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
   C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny, P.;
   De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de Torres,
   A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado,
   H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Drazinos,
   P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.; Esquej, P.;
   Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão,
   A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernique,
   P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile,
   E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
   García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
   P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.;
   Giuffrida, G.; Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier, A.;
   Guiraud, J.; Gutiérrez-Sánchez, R.; Haigron, R.; Hatzidimitriou,
   D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
   T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
   Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
   Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
   Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
   Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
   Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Lorenz, D.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.;
   McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
   D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
   R.; Morel, T.; Morgenthaler, S.; Morris, D.; Mulone, A. F.; Muraveva,
   T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane,
   W.; Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.;
   Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
   Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum,
   G.; Poggio, E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.;
   Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.;
   Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers,
   T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
   L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
   Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
   Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.;
   Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.;
   Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
   Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.;
   Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szegedi-Elek,
   E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira,
   R.; Terrett, D.; Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra
   Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant,
   M.; Valentini, G.; Valette, V.; van Elteren, A.; Van Hemelryck,
   E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato, A.; Veljanoski, J.;
   Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba,
   V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz, O.; Wevers, T.;
   Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour, H.; Zorec, J.;
   Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2019A&A...623A.110G    Altcode: 2018arXiv180409382G
  Context. The ESA Gaia mission provides a unique time-domain survey
  for more than 1.6 billion sources with G ≲ 21 mag. <BR /> Aims:
  We showcase stellar variability in the Galactic colour-absolute
  magnitude diagram (CaMD). We focus on pulsating, eruptive, and
  cataclysmic variables, as well as on stars that exhibit variability
  that is due to rotation and eclipses. <BR /> Methods: We describe
  the locations of variable star classes, variable object fractions,
  and typical variability amplitudes throughout the CaMD and show
  how variability-related changes in colour and brightness induce
  "motions". To do this, we use 22 months of calibrated photometric,
  spectro-photometric, and astrometric Gaia data of stars with a
  significant parallax. To ensure that a large variety of variable
  star classes populate the CaMD, we crossmatched Gaia sources with
  known variable stars. We also used the statistics and variability
  detection modules of the Gaia variability pipeline. Corrections for
  interstellar extinction are not implemented in this article. <BR />
  Results: Gaia enables the first investigation of Galactic variable
  star populations in the CaMD on a similar, if not larger, scale as
  was previously done in the Magellanic Clouds. Although the observed
  colours are not corrected for reddening, distinct regions are visible
  in which variable stars occur. We determine variable star fractions
  to within the current detection thresholds of Gaia. Finally,
  we report the most complete description of variability-induced
  motion within the CaMD to date. <BR /> Conclusions: Gaia enables
  novel insights into variability phenomena for an unprecedented
  number of stars, which will benefit the understanding of stellar
  astrophysics. The CaMD of Galactic variable stars provides crucial
  information on physical origins of variability in a way that
  has previously only been accessible for Galactic star clusters or
  external galaxies. Future Gaia data releases will enable significant
  improvements over this preview by providing longer time series, more
  accurate astrometry, and additional data types (time series BP and
  RP spectra, RVS spectra, and radial velocities), all for much larger
  samples of stars. <P />A movie associated to Fig. 11 is available at <A
  href="https://www.aanda.org/10.1051/0004-6361/201833304/olm">https://www.aanda.org</A>.Data
  are only available at the CDS via anonymous ftp to <A
  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
  (ftp://130.79.128.5) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A110">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/623/A110</A>.

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Title: Carbon star wind models at solar and sub-solar metallicities:
    a comparative study. I. Mass loss and the properties of dust-driven
    winds
Authors: Bladh, S.; Eriksson, K.; Marigo, P.; Liljegren, S.;
   Aringer, B.
2019A&A...623A.119B    Altcode: 2019arXiv190205352B
  Context. The heavy mass loss observed in evolved stars on the
  asymptotic giant branch (AGB) is usually attributed to dust-driven
  winds, but it is still an open question how much AGB stars contribute
  to the dust production in the interstellar medium, especially at
  lower metallicities. In the case of C-type AGB stars, where the
  wind is thought to be driven by radiation pressure on amorphous
  carbon grains, there should be significant dust production even in
  metal-poor environments. Carbon stars can manufacture the building
  blocks needed to form the wind-driving dust species themselves,
  irrespective of the chemical composition they have, by dredging
  up carbon from the stellar interior during thermal pulses. <BR />
  Aims: We investigate how the mass loss in carbon stars is affected
  by a low-metallicity environment, similar to the Large and Small
  Magellanic Clouds (LMC and SMC). <BR /> Methods: The atmospheres and
  winds of C-type AGB stars are modeled with the 1D spherically symmetric
  radiation-hydrodynamical code Dynamic Atmosphere and Radiation-driven
  Wind models based on Implicit Numerics (DARWIN). The models include a
  time-dependent description for nucleation, growth, and evaporation of
  amorphous carbon grains directly out of the gas phase. To explore the
  metallicity-dependence of mass loss we calculate model grids at three
  different chemical abundances (solar, LMC, and SMC). Since carbon may
  be dredged up during the thermal pulses as AGB stars evolve, we keep
  the carbon abundance as a free parameter. The models in these three
  different grids all have a current mass of one solar mass; effective
  temperatures of 2600, 2800, 3000, or 3200 K; and stellar luminosities
  equal to logL<SUB>*</SUB>/L<SUB>⊙</SUB> = 3.70, 3.85, or 4.00. <BR
  /> Results: The DARWIN models show that mass loss in carbon stars is
  facilitated by high luminosities, low effective temperatures, and a high
  carbon excess (C-O) at both solar and subsolar metallicities. Similar
  combinations of effective temperature, luminosity, and carbon excess
  produce outflows at both solar and subsolar metallicities. There
  are no large systematic differences in the mass-loss rates and wind
  velocities produced by these wind models with respect to metallicity,
  nor any systematic difference concerning the distribution of grain sizes
  or how much carbon is condensed into dust. DARWIN models at subsolar
  metallicity have approximately 15% lower mass-loss rates compared to
  DARWIN models at solar metallicity with the same stellar parameters and
  carbon excess. For both solar and subsolar environments typical grain
  sizes range between 0.1 and 0.5 μm, the degree of condensed carbon
  varies between 5 and 40%, and the gas-to-dust ratios between 500 and
  10 000. <BR /> Conclusions: C-type AGB stars can contribute to the
  dust production at subsolar metallicities (down to at least [Fe/H] =
  -1) as long as they dredge up sufficient amounts of carbon from the
  stellar interior. Furthermore, stellar evolution models can use the
  mass-loss rates calculated from DARWIN models at solar metallicity when
  modeling the AGB phase at subsolar metallicities if carbon excess is
  used as the critical abundance parameter instead of the C/O ratio.

---------------------------------------------------------
Title: Gaia Data Release 2. Observations of solar system objects
Authors: Gaia Collaboration; Spoto, F.; Tanga, P.; Mignard, F.;
   Berthier, J.; Carry, B.; Cellino, A.; Dell'Oro, A.; Hestroffer, D.;
   Muinonen, K.; Pauwels, T.; Petit, J. -M.; David, P.; De Angeli, F.;
   Delbo, M.; Frézouls, B.; Galluccio, L.; Granvik, M.; Guiraud, J.;
   Hernández, J.; Ordénovic, C.; Portell, J.; Poujoulet, E.; Thuillot,
   W.; Walmsley, G.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de
   Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.; Biermann,
   M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner, S. A.;
   Lammers, U.; Lindegren, L.; Luri, X.; Panem, C.; Pourbaix, D.; Randich,
   S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; van Leeuwen, F.;
   Walton, N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.;
   Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.;
   Chaoul, L.; Cheek, N.; Fabricius, C.; Guerra, R.; Holl, B.; Masana,
   E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo, P.; Riello,
   M.; Seabroke, G. M.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
   G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
   Audard, M.; Bellas-Velidis, I.; Benson, K.; Blomme, R.; Burgess, P.;
   Busso, G.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson, M.; De
   Ridder, J.; Delchambre, L.; Ducourant, C.; Fernández-Hernández, J.;
   Fouesneau, M.; Frémat, Y.; García-Torres, M.; González-Núñez,
   J.; González-Vidal, J. J.; Gosset, E.; Guy, L. P.; Halbwachs,
   J. -L.; Hambly, N. C.; Harrison, D. L.; Hodgkin, S. T.; Hutton,
   A.; Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn,
   A. J.; Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Lö, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Osinde, J.; Pancino, E.; Recio-Blanco, A.; Richards, P. J.;
   Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis, C.; Smith, M.;
   Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven, W.; Abbas, U.;
   Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla, G.; Álvarez,
   M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Andrei, A. H.; Anglada
   Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
   Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barache,
   C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado,
   D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz, L.; Bassilana,
   J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.; Bertone, S.;
   Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.;
   Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon, S.; Bourda, G.;
   Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan, A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard,
   A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan,
   G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.;
   Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, M.; de Laverny, P.;
   De Luise, F.; De March, R.; de Souza, R.; de Torres, A.; Debosscher,
   J.; del Pozo, E.; Delgado, A.; Delgado, H. E.; Diakite, S.; Diener,
   C.; Distefano, E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson,
   B.; Enke, H.; Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre,
   C.; Fabrizio, M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.;
   Federici, L.; Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.;
   Findeisen, K.; Fonti, A.; Fraile, E.; Fraser, M.; Gai, M.; Galleti, S.;
   Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
   A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
   Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Gueguen, A.; Guerrier,
   A.; Gutié, R.; Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood,
   M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger, T.; Hobbs, D.; Hofmann,
   W.; Holland, G.; Huckle, H. E.; Hypki, A.; Icardi, V.; Janßen, K.;
   Jevardat de Fombelle, G.; Jonker, P. G.; Juhász, Á. L.; Julbe,
   F.; Karampelas, A.; Kewley, A.; Klar, J.; Kochoska, A.; Kohley, R.;
   Kolenberg, K.; Kontizas, M.; Kontizas, E.; Koposov, S. E.; Kordopatis,
   G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.; Lambert, S.; Lanza, A. F.;
   Lasne, Y.; Lavigne, J. -B.; Le Fustec, Y.; Le Poncin-Lafitte, C.;
   Lebreton, Y.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt,
   H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
   T. A.; Livanou, E.; Lobel, A.; López, M.; Managau, S.; Mann, R. G.;
   Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni,
   S.; Marschalkó, G.; Marshall, D. J.; Martino, M.; Marton, G.; Mary,
   N.; Massari, D.; Matijevič, G.; Mazeh, T.; McMillan, P. J.; Messina,
   S.; Michalik, D.; Millar, N. R.; Molina, D.; Molinaro, R.; Molnár,
   L.; Montegriffo, P.; Mor, R.; Morbidelli, R.; Morel, T.; Morris, D.;
   Mulone, A. F.; Muraveva, T.; Musella, I.; Nelemans, G.; Nicastro, L.;
   Noval, L.; O'Mullane, W.; Ordóñez-Blanco, D.; Osborne, P.; Pagani,
   C.; Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
   Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.;
   Poggio, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux,
   N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.; Riclet, F.; Ripepi,
   V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers, T.; Roelens, M.;
   Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski,
   G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.; Salguero, E.;
   Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.; Schultheis, M.;
   Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.; Shih, I. -C.;
   Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.; Solano, E.;
   Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.; Spagna, A.;
   Stampa, U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.;
   Stoev, H.; Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.;
   Tapiador, D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.;
   Terrett, D.; Teyssandier, P.; Titarenko, A.; Torra Clotet, F.; Turon,
   C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.;
   Valette, V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.;
   Vaschetto, M.; Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente,
   D.; Vogt, S.; von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.;
   Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
   Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
   Zurbach, C.; Zwitter, T.
2018A&A...616A..13G    Altcode: 2018arXiv180409379G
  Context. The Gaia spacecraft of the European Space Agency (ESA)
  has been securing observations of solar system objects (SSOs) since
  the beginning of its operations. Data Release 2 (DR2) contains the
  observations of a selected sample of 14,099 SSOs. These asteroids have
  been already identified and have been numbered by the Minor Planet
  Center repository. Positions are provided for each Gaia observation at
  CCD level. As additional information, complementary to astrometry, the
  apparent brightness of SSOs in the unfiltered G band is also provided
  for selected observations. <BR /> Aims: We explain the processing of SSO
  data, and describe the criteria we used to select the sample published
  in Gaia DR2. We then explore the data set to assess its quality. <BR />
  Methods: To exploit the main data product for the solar system in Gaia
  DR2, which is the epoch astrometry of asteroids, it is necessary to take
  into account the unusual properties of the uncertainty, as the position
  information is nearly one-dimensional. When this aspect is handled
  appropriately, an orbit fit can be obtained with post-fit residuals
  that are overall consistent with the a-priori error model that was used
  to define individual values of the astrometric uncertainty. The role
  of both random and systematic errors is described. The distribution
  of residuals allowed us to identify possible contaminants in the
  data set (such as stars). Photometry in the G band was compared
  to computed values from reference asteroid shapes and to the flux
  registered at the corresponding epochs by the red and blue photometers
  (RP and BP). <BR /> Results: The overall astrometric performance is
  close to the expectations, with an optimal range of brightness G 12 -
  17. In this range, the typical transit-level accuracy is well below
  1 mas. For fainter asteroids, the growing photon noise deteriorates
  the performance. Asteroids brighter than G 12 are affected by a lower
  performance of the processing of their signals. The dramatic improvement
  brought by Gaia DR2 astrometry of SSOs is demonstrated by comparisons
  to the archive data and by preliminary tests on the detection of subtle
  non-gravitational effects.

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Title: Gaia Data Release 2. The celestial reference frame (Gaia-CRF2)
Authors: Gaia Collaboration; Mignard, F.; Klioner, S. A.; Lindegren,
   L.; Hernández, J.; Bastian, U.; Bombrun, A.; Hobbs, D.; Lammers, U.;
   Michalik, D.; Ramos-Lerate, M.; Biermann, M.; Fernández-Hernández,
   J.; Geyer, R.; Hilger, T.; Siddiqui, H. I.; Steidelmüller, H.;
   Babusiaux, C.; Barache, C.; Lambert, S.; Andrei, A. H.; Bourda, G.;
   Charlot, P.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
   J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen, F.;
   Jordi, C.; Luri, X.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti,
   P.; Soubiran, C.; van Leeuwen, F.; Walton, N. A.; Arenou, F.; Cropper,
   M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.; Bakker, J.; Cacciari,
   C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius,
   C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.; Mowlavi, N.;
   Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello, M.; Seabroke,
   G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.; Comoretto,
   G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.; Andrae, R.;
   Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier, J.; Blomme,
   R.; Burgess, P.; Busso, G.; Carry, B.; Cellino, A.; Clementini, G.;
   Clotet, M.; Creevey, O.; Davidson, M.; De Ridder, J.; Delchambre, L.;
   Dell'Oro, A.; Ducourant, C.; Fouesneau, M.; Frémat, Y.; Galluccio,
   L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz, G.;
   Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins, A.;
   Lanzafame, A. C.; Lebzelter, T.; Löffler, W.; Manteiga, M.; Marrese,
   P. M.; Martín-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
   Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.;
   Richards, P. J.; Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis,
   C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven,
   W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla,
   G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Anglada
   Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja, T. L.;
   Bach, N.; Baker, S. G.; Balaguer-Núñez, L.; Balm, P.; Barata, C.;
   Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado, D.; Barros, M.;
   Barstow, M. A.; Bartholomé Muñoz, L.; Bassilana, J. -L.; Becciani,
   U.; Bellazzini, M.; Berihuete, A.; Bertone, S.; Bianchi, L.; Bienaymé,
   O.; Blanco-Cuaresma, S.; Boch, T.; Boeche, C.; Borrachero, R.;
   Bossini, D.; Bouquillon, S.; Bragaglia, A.; Bramante, L.; Breddels,
   M. A.; Bressan, A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.;
   Bucciarelli, B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi,
   R.; Caffau, E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin,
   T.; Carballo, R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.;
   Castellani, M.; Castro-Ginard, A.; Chemin, L.; Chiavassa, A.; Cocozza,
   G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.;
   Cuypers, J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
   David, M.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.;
   de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
   Delgado, H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
   Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.;
   Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler,
   S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.;
   Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.;
   Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato,
   D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
   P.; Gerssen, J.; Giacobbe, P.; Gilmore, G.; Girona, S.; Giuffrida, G.;
   Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier, A.; Guiraud,
   J.; Gutié, R.; Haigron, R.; Hatzidimitriou, D.; Hauser, M.; Haywood,
   M.; Heiter, U.; Helmi, A.; Heu, J.; Hofmann, W.; Holland, G.; Huckle,
   H. E.; Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.;
   Jonker, P. G.; Juhász, A. L.; Julbe, F.; Karampelas, A.; Kewley,
   A.; Klar, J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.;
   Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska,
   Z.; Koubsky, P.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.;
   Mazeh, T.; McMillan, P. J.; Messina, S.; Millar, N. R.; Molina, D.;
   Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
   R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
   Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
   Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler,
   F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni,
   A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet,
   E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.;
   Regibo, S.; Reylé, C.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard,
   A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell,
   N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.;
   Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.;
   Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.;
   Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
   A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
   R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa, U.;
   Steele, I. A.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej,
   J.; Szabados, L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran,
   G.; Taylor, M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.;
   Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla,
   A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.; Valette,
   V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto,
   M.; Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.;
   von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
   Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
   Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
   Zurbach, C.; Zwitter, T.
2018A&A...616A..14G    Altcode: 2018arXiv180409377M
  Context. The second release of Gaia data (Gaia DR2) contains the
  astrometric parameters for more than half a million quasars. This set
  defines a kinematically non-rotating reference frame in the optical
  domain. A subset of these quasars have accurate VLBI positions
  that allow the axes of the reference frame to be aligned with the
  International Celestial Reference System (ICRF) radio frame. <BR
  /> Aims: We describe the astrometric and photometric properties of
  the quasars that were selected to represent the celestial reference
  frame of Gaia DR2 (Gaia-CRF2), and to compare the optical and radio
  positions for sources with accurate VLBI positions. <BR /> Methods:
  Descriptive statistics are used to characterise the overall properties
  of the quasar sample. Residual rotation and orientation errors and
  large-scale systematics are quantified by means of expansions in vector
  spherical harmonics. Positional differences are calculated relative to
  a prototype version of the forthcoming ICRF3. <BR /> Results: Gaia-CRF2
  consists of the positions of a sample of 556 869 sources in Gaia DR2,
  obtained from a positional cross-match with the ICRF3-prototype and
  AllWISE AGN catalogues. The sample constitutes a clean, dense, and
  homogeneous set of extragalactic point sources in the magnitude range
  G ≃ 16 to 21 mag with accurately known optical positions. The median
  positional uncertainty is 0.12 mas for G &lt; 18 mag and 0.5 mas at
  G = mag. Large-scale systematics are estimated to be in the range 20
  to 30 μas. The accuracy claims are supported by the parallaxes and
  proper motions of the quasars in Gaia DR2. The optical positions for
  a subset of 2820 sources in common with the ICRF3-prototype show very
  good overall agreement with the radio positions, but several tens of
  sources have significantly discrepant positions. <BR /> Conclusions:
  Based on less than 40% of the data expected from the nominal Gaia
  mission, Gaia-CRF2 is the first realisation of a non-rotating global
  optical reference frame that meets the ICRS prescriptions, meaning
  that it is built only on extragalactic sources. Its accuracy matches
  the current radio frame of the ICRF, but the density of sources in
  all parts of the sky is much higher, except along the Galactic equator.

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Title: Gaia Data Release 2. Mapping the Milky Way disc kinematics
Authors: Gaia Collaboration; Katz, D.; Antoja, T.; Romero-Gómez, M.;
   Drimmel, R.; Reylé, C.; Seabroke, G. M.; Soubiran, C.; Babusiaux,
   C.; Di Matteo, P.; Figueras, F.; Poggio, E.; Robin, A. C.; Evans,
   D. W.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
   J. H. J.; Bailer-Jones, C. A. L.; Biermann, M.; Eyer, L.; Jansen,
   F.; Jordi, C.; Klioner, S. A.; Lammers, U.; Lindegren, L.; Luri,
   X.; Mignard, F.; Panem, C.; Pourbaix, D.; Randich, S.; Sartoretti,
   P.; Siddiqui, H. I.; van Leeuwen, F.; Walton, N. A.; Arenou, F.;
   Bastian, U.; Cropper, M.; Lattanzi, M. G.; Bakker, J.; Cacciari,
   C.; Casta n, J.; Chaoul, L.; Cheek, N.; De Angeli, F.; Fabricius,
   C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.; Mowlavi, N.;
   Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello, M.; Tanga, P.;
   Thévenin, F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.;
   Teyssier, D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis,
   I.; Benson, K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.;
   Carry, B.; Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.;
   Davidson, M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant,
   C.; Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio,
   L.; García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
   J. -M.; Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro,
   L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.;
   van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
   Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
   R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
   Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
   Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
   P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
   L.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
   Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
   T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
   S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan,
   A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli,
   B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
   E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo,
   R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
   Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza,
   G.; Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.;
   Cuypers, J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.;
   David, M.; de Laverny, P.; De Luise, F.; De March, R.; de Souza, R.;
   de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
   Delgado, H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.;
   Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.;
   Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler,
   S.; Falc a, A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.;
   Fernique, P.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile, E.;
   Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
   García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
   P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
   S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.;
   Guerrier, A.; Guiraud, J.; Gutié, R.; Haigron, R.; Hatzidimitriou,
   D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
   T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
   Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
   Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
   Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
   Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
   Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.; Mazeh,
   T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
   D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
   R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
   Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
   Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler,
   F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni,
   A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poujoulet, E.; Prša,
   A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate,
   M.; Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon,
   G.; Roegiers, T.; Roelens, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
   L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
   Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
   Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan,
   D.; Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith,
   K. W.; Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay,
   J.; Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller,
   H.; Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szabados,
   L.; Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor,
   M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.; Thuillot, W.;
   Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.;
   Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.; van Elteren,
   A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato,
   A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.;
   Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz,
   O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
   H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2018A&A...616A..11G    Altcode: 2018arXiv180409380G
  Context. The second Gaia data release (Gaia DR2) contains high-precision
  positions, parallaxes, and proper motions for 1.3 billion sources as
  well as line-of-sight velocities for 7.2 million stars brighter than
  G<SUB>RVS</SUB> = 12 mag. Both samples provide a full sky coverage. <BR
  /> Aims: To illustrate the potential of Gaia DR2, we provide a first
  look at the kinematics of the Milky Way disc, within a radius of several
  kiloparsecs around the Sun. <BR /> Methods: We benefit for the first
  time from a sample of 6.4 million F-G-K stars with full 6D phase-space
  coordinates, precise parallaxes (σ<SUB>ϖ</SUB>/ϖ ≤ 20%), and
  precise Galactic cylindrical velocities (median uncertainties of 0.9-1.4
  km s<SUP>-1</SUP> and 20% of the stars with uncertainties smaller than
  1 km s<SUP>-1</SUP> on all three components). From this sample, we
  extracted a sub-sample of 3.2 million giant stars to map the velocity
  field of the Galactic disc from 5 kpc to 13 kpc from the Galactic
  centre and up to 2 kpc above and below the plane. We also study the
  distribution of 0.3 million solar neighbourhood stars (r &lt; 200 pc),
  with median velocity uncertainties of 0.4 km s<SUP>-1</SUP>, in velocity
  space and use the full sample to examine how the over-densities evolve
  in more distant regions. <BR /> Results: Gaia DR2 allows us to draw 3D
  maps of the Galactocentric median velocities and velocity dispersions
  with unprecedented accuracy, precision, and spatial resolution. The
  maps show the complexity and richness of the velocity field of the
  galactic disc. We observe streaming motions in all the components of
  the velocities as well as patterns in the velocity dispersions. For
  example, we confirm the previously reported negative and positive
  galactocentric radial velocity gradients in the inner and outer disc,
  respectively. Here, we see them as part of a non-axisymmetric kinematic
  oscillation, and we map its azimuthal and vertical behaviour. We also
  witness a new global arrangement of stars in the velocity plane of
  the solar neighbourhood and in distant regions in which stars are
  organised in thin substructures with the shape of circular arches
  that are oriented approximately along the horizontal direction in the
  U - V plane. Moreover, in distant regions, we see variations in the
  velocity substructures more clearly than ever before, in particular,
  variations in the velocity of the Hercules stream. <BR /> Conclusions:
  Gaia DR2 provides the largest existing full 6D phase-space coordinates
  catalogue. It also vastly increases the number of available distances
  and transverse velocities with respect to Gaia DR1. Gaia DR2 offers
  a great wealth of information on the Milky Way and reveals clear
  non-axisymmetric kinematic signatures within the Galactic disc, for
  instance. It is now up to the astronomical community to explore its
  full potential.

---------------------------------------------------------
Title: Gaia Data Release 2. Observational Hertzsprung-Russell diagrams
Authors: Gaia Collaboration; Babusiaux, C.; van Leeuwen, F.;
   Barstow, M. A.; Jordi, C.; Vallenari, A.; Bossini, D.; Bressan,
   A.; Cantat-Gaudin, T.; van Leeuwen, M.; Brown, A. G. A.; Prusti,
   T.; de Bruijne, J. H. J.; Bailer-Jones, C. A. L.; Biermann, M.;
   Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers, U.;
   Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
   Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Walton,
   N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.;
   Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
   L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
   Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
   P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
   F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
   D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
   K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
   Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
   M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
   Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
   García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pancino, E.; Pauwels, T.; Petit,
   J. -M.; Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Robin,
   A. C.; Sarro, L. M.; Siopis, C.; Smith, M.; Sozzetti, A.; Süveges,
   M.; Torra, J.; van Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart,
   S.; Aerts, C.; Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves,
   J.; Anderson, R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.;
   Antoja, T.; Arcay, B.; Astraatmadja, T. L.; Bach, N.; Baker, S. G.;
   Balaguer-Núñez, L.; Balm, P.; Barache, C.; Barata, C.; Barbato,
   D.; Barblan, F.; Barklem, P. S.; Barrado, D.; Barros, M.; Bartholomé
   Muñoz, L.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete,
   A.; Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.;
   Boch, T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bouquillon, S.;
   Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Carballo, R.; Carlucci, T.; Carrasco, J. M.;
   Casamiquela, L.; Castellani, M.; Castro-Ginard, A.; Charlot, P.;
   Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.; Cowell,
   S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte, C.;
   Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny, P.;
   De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de Torres,
   A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.; Delgado,
   H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding, C.; Drazinos,
   P.; Durán, J.; Edvardsson, B.; Enke, H.; Eriksson, K.; Esquej, P.;
   Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler, S.; Falcão,
   A. J.; Farràs Casas, M.; Federici, L.; Fedorets, G.; Fernique,
   P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.; Fraile,
   E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.; Garabato, D.;
   García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
   P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona,
   S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.;
   Guerrier, A.; Guiraud, J.; Gutié, R.; Haigron, R.; Hatzidimitriou,
   D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
   T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
   Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
   Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
   Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
   Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
   Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; López,
   M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant,
   J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall, D. J.;
   Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič, G.; Mazeh,
   T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
   D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor, R.; Morbidelli,
   R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
   Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordénovic, C.;
   Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.;
   Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.;
   Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prša,
   A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate,
   M.; Regibo, S.; Reylé, C.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard,
   A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.; Rowell,
   N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés, T.;
   Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros, T.;
   Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol, M.;
   Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
   A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
   R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa,
   U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
   Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador,
   D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett,
   D.; Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.;
   Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini,
   G.; Valette, V.; van Elteren, A.; Van Hemelryck, E.; Vaschetto, M.;
   Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.;
   von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
   Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.;
   Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
   Zurbach, C.; Zwitter, T.
2018A&A...616A..10G    Altcode: 2018arXiv180409378G
  Context. Gaia Data Release 2 provides high-precision astrometry and
  three-band photometry for about 1.3 billion sources over the full
  sky. The precision, accuracy, and homogeneity of both astrometry and
  photometry are unprecedented. <BR /> Aims: We highlight the power of
  the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell
  diagram (HRD). Gaia allows us to present many different HRDs, depending
  in particular on stellar population selections. We do not aim here
  for completeness in terms of types of stars or stellar evolutionary
  aspects. Instead, we have chosen several illustrative examples. <BR />
  Methods: We describe some of the selections that can be made in Gaia
  DR2 to highlight the main structures of the Gaia HRDs. We select both
  field and cluster (open and globular) stars, compare the observations
  with previous classifications and with stellar evolutionary tracks,
  and we present variations of the Gaia HRD with age, metallicity, and
  kinematics. Late stages of stellar evolution such as hot subdwarfs,
  post-AGB stars, planetary nebulae, and white dwarfs are also analysed,
  as well as low-mass brown dwarf objects. <BR /> Results: The Gaia HRDs
  are unprecedented in both precision and coverage of the various Milky
  Way stellar populations and stellar evolutionary phases. Many fine
  structures of the HRDs are presented. The clear split of the white
  dwarf sequence into hydrogen and helium white dwarfs is presented
  for the first time in an HRD. The relation between kinematics and the
  HRD is nicely illustrated. Two different populations in a classical
  kinematic selection of the halo are unambiguously identified in the
  HRD. Membership and mean parameters for a selected list of open
  clusters are provided. They allow drawing very detailed cluster
  sequences, highlighting fine structures, and providing extremely
  precise empirical isochrones that will lead to more insight in
  stellar physics. <BR /> Conclusions: Gaia DR2 demonstrates the
  potential of combining precise astrometry and photometry for large
  samples for studies in stellar evolution and stellar population
  and opens an entire new area for HRD-based studies. <P />The full
  Table A.1 is only available at the CDS via anonymous ftp to <A
  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A
  href="http://cdsarc.u-strasbg.fr">http://130.79.128.5</A>) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A10">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A10</A>

---------------------------------------------------------
Title: Gaia Data Release 2. Kinematics of globular clusters and
    dwarf galaxies around the Milky Way
Authors: Gaia Collaboration; Helmi, A.; van Leeuwen, F.; McMillan,
   P. J.; Massari, D.; Antoja, T.; Robin, A. C.; Lindegren, L.;
   Bastian, U.; Arenou, F.; Babusiaux, C.; Biermann, M.; Breddels,
   M. A.; Hobbs, D.; Jordi, C.; Pancino, E.; Reylé, C.; Veljanoski,
   J.; Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne,
   J. H. J.; Bailer-Jones, C. A. L.; Evans, D. W.; Eyer, L.; Jansen,
   F.; Klioner, S. A.; Lammers, U.; Luri, X.; Mignard, F.; Panem,
   C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
   Soubiran, C.; Walton, N. A.; Cropper, M.; Drimmel, R.; Katz, D.;
   Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castañeda, J.; Chaoul,
   L.; Cheek, N.; De Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
   Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
   P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thévenin,
   F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
   D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
   K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
   Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
   M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
   Fernández-Hernández, J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.;
   García-Torres, M.; González-Núñez, J.; González-Vidal, J. J.;
   Gosset, E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison,
   D. L.; Hernández, J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.;
   Jasniewicz, G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.;
   Krone-Martins, A.; Lanzafame, A. C.; Lebzelter, T.; Löffler, W.;
   Manteiga, M.; Marrese, P. M.; Martín-Fleitas, J. M.; Moitinho, A.;
   Mora, A.; Muinonen, K.; Osinde, J.; Pauwels, T.; Petit, J. -M.;
   Recio-Blanco, A.; Richards, P. J.; Rimoldini, L.; Sarro, L. M.;
   Siopis, C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van
   Reeven, W.; Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.;
   Altavilla, G.; Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson,
   R. I.; Andrei, A. H.; Anglada Varela, E.; Antiche, E.; Arcay, B.;
   Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
   Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
   P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
   S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
   Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
   T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
   S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Bressan, A.; Brouillet,
   N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli, B.; Burlacu, A.;
   Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau, E.; Cancelliere,
   R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard, A.;
   Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan, G.;
   Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers, J.; Dafonte,
   C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de Laverny,
   P.; De Luise, F.; De March, R.; de Martino, D.; de Souza, R.; de
   Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado, A.;
   Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
   E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
   Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
   M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
   Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
   Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.;
   Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
   A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
   Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen,
   A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.; Hofmann,
   W.; Holland, G.; Huckle, H. E.; Hypki, A.; Icardi, V.; Janßen, K.;
   Jevardat de Fombelle, G.; Jonker, P. G.; Juhász, Á. L.; Julbe,
   F.; Karampelas, A.; Kewley, A.; Klar, J.; Kochoska, A.; Kohley, R.;
   Kolenberg, K.; Kontizas, M.; Kontizas, E.; Koposov, S. E.; Kordopatis,
   G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.; Lambert, S.; Lanza, A. F.;
   Lasne, Y.; Lavigne, J. -B.; Le Fustec, Y.; Le Poncin-Lafitte, C.;
   Lebreton, Y.; Leccia, S.; Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt,
   H.; Leroux, F.; Liao, S.; Licata, E.; Lindstrøm, H. E. P.; Lister,
   T. A.; Livanou, E.; Lobel, A.; López, M.; Managau, S.; Mann, R. G.;
   Mantelet, G.; Marchal, O.; Marchant, J. M.; Marconi, M.; Marinoni,
   S.; Marschalkó, G.; Marshall, D. J.; Martino, M.; Marton, G.; Mary,
   N.; Matijevič, G.; Mazeh, T.; Messina, S.; Michalik, D.; Millar,
   N. R.; Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor,
   R.; Morbidelli, R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva,
   T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.;
   Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano,
   I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.;
   Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.;
   Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux,
   N.; Ramos-Lerate, M.; Regibo, S.; Riclet, F.; Ripepi, V.; Riva, A.;
   Rivard, A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gómez, M.;
   Rowell, N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagristà Sellés,
   T.; Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros,
   T.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol,
   M.; Segovia, J. C.; Ségransan, D.; Shih, I. -C.; Siltala, L.; Silva,
   A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
   R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa,
   U.; Steele, I. A.; Steidelmüller, H.; Stephenson, C. A.; Stoev, H.;
   Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador,
   D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.;
   Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.;
   Turon, C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini,
   G.; Valette, V.; van Elteren, A.; Van Hemelryck, E.; van Leeuwen,
   M.; Vaschetto, M.; Vecchiato, A.; Viala, Y.; Vicente, D.; Vogt, S.;
   von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
   Weiler, M.; Wertz, O.; Wevems, T.; Wyrzykowski, Ł.; Yoldas, A.;
   Žerjal, M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.;
   Zurbach, C.; Zwitter, T.
2018A&A...616A..12G    Altcode: 2018arXiv180409381G
  Note to the Readers: Following the publication of the <A
  href="https://www.aanda.org/articles/aa/full_html/2020/05/aa32698e-18/aa32698e-18.html">corrigendum</A>,
  the article was corrected on 15 May 2020. <P />Context. <BR /> Aims:
  The goal of this paper is to demonstrate the outstanding quality
  of the second data release of the Gaia mission and its power for
  constraining many different aspects of the dynamics of the satellites
  of the Milky Way. We focus here on determining the proper motions of
  75 Galactic globular clusters, nine dwarf spheroidal galaxies, one
  ultra-faint system, and the Large and Small Magellanic Clouds. <BR
  /> Methods: Using data extracted from the Gaia archive, we derived
  the proper motions and parallaxes for these systems, as well as
  their uncertainties. We demonstrate that the errors, statistical
  and systematic, are relatively well understood. We integrated the
  orbits of these objects in three different Galactic potentials, and
  characterised their properties. We present the derived proper motions,
  space velocities, and characteristic orbital parameters in various
  tables to facilitate their use by the astronomical community. <BR />
  Results: Our limited and straightforward analyses have allowed us
  for example to (i) determine absolute and very precise proper motions
  for globular clusters; (ii) detect clear rotation signatures in the
  proper motions of at least five globular clusters; (iii) show that
  the satellites of the Milky Way are all on high-inclination orbits,
  but that they do not share a single plane of motion; (iv) derive a lower
  limit for the mass of the Milky Way of 9.1<SUB>-2.6</SUB><SUP>+6.2</SUP>
  × 10<SUP>11</SUP> M<SUB>⊙</SUB> based on the assumption that the Leo
  I dwarf spheroidal is bound; (v) derive a rotation curve for the Large
  Magellanic Cloud based solely on proper motions that is competitive
  with line-of-sight velocity curves, now using many orders of magnitude
  more sources; and (vi) unveil the dynamical effect of the bar on the
  motions of stars in the Large Magellanic Cloud. <BR /> Conclusions: All
  these results highlight the incredible power of the Gaia astrometric
  mission, and in particular of its second data release. <P />Full
  Table D.3 is only available at the CDS via anonymous ftp to <A
  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A> (<A
  href="http://cdsarc.u-strasbg.fr">http://130.79.128.5</A>) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A12">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/616/A12</A>

---------------------------------------------------------
Title: Gaia Data Release 2. Summary of the contents and survey
    properties
Authors: Gaia Collaboration; Brown, A. G. A.; Vallenari, A.; Prusti,
   T.; de Bruijne, J. H. J.; Babusiaux, C.; Bailer-Jones, C. A. L.;
   Biermann, M.; Evans, D. W.; Eyer, L.; Jansen, F.; Jordi, C.; Klioner,
   S. A.; Lammers, U.; Lindegren, L.; Luri, X.; Mignard, F.; Panem,
   C.; Pourbaix, D.; Randich, S.; Sartoretti, P.; Siddiqui, H. I.;
   Soubiran, C.; van Leeuwen, F.; Walton, N. A.; Arenou, F.; Bastian,
   U.; Cropper, M.; Drimmel, R.; Katz, D.; Lattanzi, M. G.; Bakker,
   J.; Cacciari, C.; Castañeda, J.; Chaoul, L.; Cheek, N.; De Angeli,
   F.; Fabricius, C.; Guerra, R.; Holl, B.; Masana, E.; Messineo, R.;
   Mowlavi, N.; Nienartowicz, K.; Panuzzo, P.; Portell, J.; Riello,
   M.; Seabroke, G. M.; Tanga, P.; Thévenin, F.; Gracia-Abril, G.;
   Comoretto, G.; Garcia-Reinaldos, M.; Teyssier, D.; Altmann, M.;
   Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson, K.; Berthier,
   J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.; Cellino, A.;
   Clementini, G.; Clotet, M.; Creevey, O.; Davidson, M.; De Ridder, J.;
   Delchambre, L.; Dell'Oro, A.; Ducourant, C.; Fernández-Hernández,
   J.; Fouesneau, M.; Frémat, Y.; Galluccio, L.; García-Torres,
   M.; González-Núñez, J.; González-Vidal, J. J.; Gosset, E.; Guy,
   L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.; Hernández,
   J.; Hestroffer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz, G.;
   Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins, A.;
   Lanzafame, A. C.; Lebzelter, T.; Löffler, W.; Manteiga, M.; Marrese,
   P. M.; Martín-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
   Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.;
   Richards, P. J.; Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis,
   C.; Smith, M.; Sozzetti, A.; Süveges, M.; Torra, J.; van Reeven, W.;
   Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla, G.;
   Álvarez, M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Andrei,
   A. H.; Anglada Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.;
   Astraatmadja, T. L.; Bach, N.; Baker, S. G.; Balaguer-Núñez, L.;
   Balm, P.; Barache, C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem,
   P. S.; Barrado, D.; Barros, M.; Barstow, M. A.; Bartholomé Muñoz,
   S.; Bassilana, J. -L.; Becciani, U.; Bellazzini, M.; Berihuete, A.;
   Bertone, S.; Bianchi, L.; Bienaymé, O.; Blanco-Cuaresma, S.; Boch,
   T.; Boeche, C.; Bombrun, A.; Borrachero, R.; Bossini, D.; Bouquillon,
   S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels, M. A.; Bressan,
   A.; Brouillet, N.; Brüsemeister, T.; Brugaletta, E.; Bucciarelli,
   B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caffau,
   E.; Cancelliere, R.; Cannizzaro, G.; Cantat-Gaudin, T.; Carballo,
   R.; Carlucci, T.; Carrasco, J. M.; Casamiquela, L.; Castellani, M.;
   Castro-Ginard, A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.;
   Costigan, G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypers,
   J.; Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.;
   de Laverny, P.; De Luise, F.; De March, R.; de Martino, D.; de Souza,
   R.; de Torres, A.; Debosscher, J.; del Pozo, E.; Delbo, M.; Delgado,
   A.; Delgado, H. E.; Di Matteo, P.; Diakite, S.; Diener, C.; Distefano,
   E.; Dolding, C.; Drazinos, P.; Durán, J.; Edvardsson, B.; Enke, H.;
   Eriksson, K.; Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio,
   M.; Faigler, S.; Falcão, A. J.; Farràs Casas, M.; Federici, L.;
   Fedorets, G.; Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.;
   Fonti, A.; Fraile, E.; Fraser, M.; Frézouls, B.; Gai, M.; Galleti, S.;
   Garabato, D.; García-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel,
   A.; Gavras, P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.;
   Girona, S.; Giuffrida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen,
   A.; Guerrier, A.; Guiraud, J.; Gutiérrez-Sánchez, R.; Haigron, R.;
   Hatzidimitriou, D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.;
   Heu, J.; Hilger, T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle,
   H. E.; Hypki, A.; Icardi, V.; Janßen, K.; Jevardat de Fombelle, G.;
   Jonker, P. G.; Juhász, Á. L.; Julbe, F.; Karampelas, A.; Kewley,
   A.; Klar, J.; Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.;
   Kontizas, E.; Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.;
   Koubsky, P.; Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.;
   Le Fustec, Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.;
   Leclerc, N.; Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.;
   Licata, E.; Lindstrøm, H. E. P.; Lister, T. A.; Livanou, E.; Lobel,
   A.; López, M.; Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.;
   Marchant, J. M.; Marconi, M.; Marinoni, S.; Marschalkó, G.; Marshall,
   D. J.; Martino, M.; Marton, G.; Mary, N.; Massari, D.; Matijevič,
   G.; Mazeh, T.; McMillan, P. J.; Messina, S.; Michalik, D.; Millar,
   N. R.; Molina, D.; Molinaro, R.; Molnár, L.; Montegriffo, P.; Mor,
   R.; Morbidelli, R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva,
   T.; Musella, I.; Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane,
   W.; Ordénovic, C.; Ordóñez-Blanco, D.; Osborne, P.; Pagani, C.;
   Pagano, I.; Pailler, F.; Palacin, H.; Palaversa, L.; Panahi, A.;
   Pawlak, M.; Piersimoni, A. M.; Pineau, F. -X.; Plachy, E.; Plum,
   G.; Poggio, E.; Poujoulet, E.; Prša, A.; Pulone, L.; Racero, E.;
   Ragaini, S.; Rambaux, N.; Ramos-Lerate, M.; Regibo, S.; Reylé, C.;
   Riclet, F.; Ripepi, V.; Riva, A.; Rivard, A.; Rixon, G.; Roegiers,
   T.; Roelens, M.; Romero-Gómez, M.; Rowell, N.; Royer, F.; Ruiz-Dern,
   L.; Sadowski, G.; Sagristà Sellés, T.; Sahlmann, J.; Salgado, J.;
   Salguero, E.; Sanna, N.; Santana-Ros, T.; Sarasso, M.; Savietto, H.;
   Schultheis, M.; Sciacca, E.; Segol, M.; Segovia, J. C.; Ségransan, D.;
   Shih, I. -C.; Siltala, L.; Silva, A. F.; Smart, R. L.; Smith, K. W.;
   Solano, E.; Solitro, F.; Sordo, R.; Soria Nieto, S.; Souchay, J.;
   Spagna, A.; Spoto, F.; Stampa, U.; Steele, I. A.; Steidelmüller, H.;
   Stephenson, C. A.; Stoev, H.; Suess, F. F.; Surdej, J.; Szabados, L.;
   Szegedi-Elek, E.; Tapiador, D.; Taris, F.; Tauran, G.; Taylor,
   M. B.; Teixeira, R.; Terrett, D.; Teyssandier, P.; Thuillot, W.;
   Titarenko, A.; Torra Clotet, F.; Turon, C.; Ulla, A.; Utrilla, E.;
   Uzzi, S.; Vaillant, M.; Valentini, G.; Valette, V.; van Elteren,
   A.; Van Hemelryck, E.; van Leeuwen, M.; Vaschetto, M.; Vecchiato,
   A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.; von Essen, C.;
   Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.; Weiler, M.; Wertz,
   O.; Wevers, T.; Wyrzykowski, Ł.; Yoldas, A.; Žerjal, M.; Ziaeepour,
   H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.; Zwitter, T.
2018A&A...616A...1G    Altcode: 2018arXiv180409365G
  Context. We present the second Gaia data release, Gaia DR2, consisting
  of astrometry, photometry, radial velocities, and information on
  astrophysical parameters and variability, for sources brighter than
  magnitude 21. In addition epoch astrometry and photometry are provided
  for a modest sample of minor planets in the solar system. <BR />
  Aims: A summary of the contents of Gaia DR2 is presented, accompanied
  by a discussion on the differences with respect to Gaia DR1 and
  an overview of the main limitations which are still present in
  the survey. Recommendations are made on the responsible use of
  Gaia DR2 results. <BR /> Methods: The raw data collected with the
  Gaia instruments during the first 22 months of the mission have
  been processed by the Gaia Data Processing and Analysis Consortium
  (DPAC) and turned into this second data release, which represents
  a major advance with respect to Gaia DR1 in terms of completeness,
  performance, and richness of the data products. <BR /> Results: Gaia
  DR2 contains celestial positions and the apparent brightness in G for
  approximately 1.7 billion sources. For 1.3 billion of those sources,
  parallaxes and proper motions are in addition available. The sample
  of sources for which variability information is provided is expanded
  to 0.5 million stars. This data release contains four new elements:
  broad-band colour information in the form of the apparent brightness
  in the G<SUB>BP</SUB> (330-680 nm) and G<SUB>RP</SUB> (630-1050 nm)
  bands is available for 1.4 billion sources; median radial velocities for
  some 7 million sources are presented; for between 77 and 161 million
  sources estimates are provided of the stellar effective temperature,
  extinction, reddening, and radius and luminosity; and for a pre-selected
  list of 14 000 minor planets in the solar system epoch astrometry
  and photometry are presented. Finally, Gaia DR2 also represents a
  new materialisation of the celestial reference frame in the optical,
  the Gaia-CRF2, which is the first optical reference frame based solely
  on extragalactic sources. There are notable changes in the photometric
  system and the catalogue source list with respect to Gaia DR1, and we
  stress the need to consider the two data releases as independent. <BR
  /> Conclusions: Gaia DR2 represents a major achievement for the Gaia
  mission, delivering on the long standing promise to provide parallaxes
  and proper motions for over 1 billion stars, and representing a first
  step in the availability of complementary radial velocity and source
  astrophysical information for a sample of stars in the Gaia survey
  which covers a very substantial fraction of the volume of our galaxy.

---------------------------------------------------------
Title: VizieR Online Data Catalog: 46 open clusters GaiaDR2 HR
    diagrams (Gaia Collaboration, 2018)
Authors: Gaia Collaboration; Babusiaux, C.; van Leeuwen, F.;
   Barstow; M., A.; Jordi, C.; Vallenari, A.; Bossini, A.; Bressan,
   A.; Cantat-Gaudin, T.; van Leeuwen, M.; Brown, A. G. A.; Prusti,
   T.; de Bruijne, J. H. J.; Bailer-Jones, C. A. L.; Biermann, M.;
   Evans, D. W.; Eyer, L.; Jansen, F.; Klioner, S. A.; Lammers, U.;
   Lindegren, L.; Luri, X.; Mignard, F.; Panem, C.; Pourbaix, D.;
   Randich, S.; Sartoretti, P.; Siddiqui, H. I.; Soubiran, C.; Walton,
   N. A.; Arenou, F.; Bastian, U.; Cropper, M.; Drimmel, R.; Katz, D.;
   Lattanzi, M. G.; Bakker, J.; Cacciari, C.; Castaneda, J.; Chaoul,
   L.; Cheek, N.; de Angeli, F.; Fabricius, C.; Guerra, R.; Holl, B.;
   Masana, E.; Messineo, R.; Mowlavi, N.; Nienartowicz, K.; Panuzzo,
   P.; Portell, J.; Riello, M.; Seabroke, G. M.; Tanga, P.; Thevenin,
   F.; Gracia-Abril, G.; Comoretto, G.; Garcia-Reinaldos, M.; Teyssier,
   D.; Altmann, M.; Andrae, R.; Audard, M.; Bellas-Velidis, I.; Benson,
   K.; Berthier, J.; Blomme, R.; Burgess, P.; Busso, G.; Carry, B.;
   Cellino, A.; Clementini, G.; Clotet, M.; Creevey, O.; Davidson,
   M.; De Ridder, J.; Delchambre, L.; Dell'Oro, A.; Ducourant, C.;
   Fernandez-Hernandez, J.; Fouesneau, M.; Fremat, Y.; Galluccio, L.;
   Garcia-Torres, M.; Gonzalez-Nunez, J.; Gonzalez-Vidal, J. J.; Gosset,
   E.; Guy, L. P.; Halbwachs, J. -L.; Hambly, N. C.; Harrison, D. L.;
   Hernandez, J.; Hestroer, D.; Hodgkin, S. T.; Hutton, A.; Jasniewicz,
   G.; Jean-Antoine-Piccolo, A.; Jordan, S.; Korn, A. J.; Krone-Martins,
   A.; Lanzafame, A. C.; Lebzelter, T.; Loeer, W.; Manteiga, M.; Marrese,
   P. M.; Martin-Fleitas, J. M.; Moitinho, A.; Mora, A.; Muinonen, K.;
   Osinde, J.; Pancino, E.; Pauwels, T.; Petit, J. -M.; Recio-Blanco, A.;
   Richards, P. J.; Rimoldini, L.; Robin, A. C.; Sarro, L. M.; Siopis,
   C.; Smith, M.; Sozzetti, A.; Sueveges, M.; Torra, J.; van Reeven, W.;
   Abbas, U.; Abreu Aramburu, A.; Accart, S.; Aerts, C.; Altavilla, G.;
   Alvarez, M. A.; Alvarez, R.; Alves, J.; Anderson, R. I.; Andrei, A. H.;
   Anglada Varela, E.; Antiche, E.; Antoja, T.; Arcay, B.; Astraatmadja,
   T. L.; Bach, N.; Baker, S. G.; Balaguer-Nunez, L.; Balm, P.; Barache,
   C.; Barata, C.; Barbato, D.; Barblan, F.; Barklem, P. S.; Barrado,
   D.; Barros, M.; Bartholome Munoz, S.; Bassilana, J. -L.; Becciani, U.;
   Bellazzini, M.; Berihuete, A.; Bertone, S.; Bianchi, L.; Bienayme, O.;
   Blanco-Cuaresma, S.; Boch, T.; Boeche, C.; Bombrun, A.; Borrachero,
   R.; Bouquillon, S.; Bourda, G.; Bragaglia, A.; Bramante, L.; Breddels,
   M. A.; Brouillet, N.; Bruesemeister, T.; Brugaletta, E.; Bucciarelli,
   B.; Burlacu, A.; Busonero, D.; Butkevich, A. G.; Buzzi, R.; Caau,
   E.; Cancelliere, R.; Cannizzaro, G.; Carballo, R.; Carlucci, T.;
   Carrasco, J. M.; Casamiquela, L.; Castellani, M.; Castro-Ginard,
   A.; Charlot, P.; Chemin, L.; Chiavassa, A.; Cocozza, G.; Costigan,
   G.; Cowell, S.; Crifo, F.; Crosta, M.; Crowley, C.; Cuypersy, J.;
   Dafonte, C.; Damerdji, Y.; Dapergolas, A.; David, P.; David, M.; de
   Laverny, P.; de Luise, F.; de March, R.; de Martino, D.; de Souza,
   R.; de Torres, A.; Debosscher, J.; Del Pozo, E.; Delbo, M.; Delgado,
   A.; Delgado, H. E.; Diakite, S.; Diener, C.; Distefano, E.; Dolding,
   C.; Drazinos, P.; Duran, J.; Edvardsson, B.; Enke, H.; Eriksson, K.;
   Esquej, P.; Eynard Bontemps, G.; Fabre, C.; Fabrizio, M.; Faigler,
   S.; Falcao, A. J.; Farras Casas, M.; Federici, L.; Fedorets, G.;
   Fernique, P.; Figueras, F.; Filippi, F.; Findeisen, K.; Fonti, A.;
   Fraile, E.; Fraser, M.; Frezouls, B.; Gai, M.; Galleti, S.; Garabato,
   D.; Garcia-Sedano, F.; Garofalo, A.; Garralda, N.; Gavel, A.; Gavras,
   P.; Gerssen, J.; Geyer, R.; Giacobbe, P.; Gilmore, G.; Girona, S.;
   Giurida, G.; Glass, F.; Gomes, M.; Granvik, M.; Gueguen, A.; Guerrier,
   A.; Guiraud, J.; Gutierrez-Sanchez, R.; Haigron, R.; Hatzidimitriou,
   D.; Hauser, M.; Haywood, M.; Heiter, U.; Helmi, A.; Heu, J.; Hilger,
   T.; Hobbs, D.; Hofmann, W.; Holland, G.; Huckle, H. E.; Hypki, A.;
   Icardi, V.; Janssen, K.; Jevardat de Fombelle, G.; Jonker, P. G.;
   Juhasz, A. L.; Julbe, F.; Karampelas, A.; Kewley, A.; Klar, J.;
   Kochoska, A.; Kohley, R.; Kolenberg, K.; Kontizas, M.; Kontizas, E.;
   Koposov, S. E.; Kordopatis, G.; Kostrzewa-Rutkowska, Z.; Koubsky, P.;
   Lambert, S.; Lanza, A. F.; Lasne, Y.; Lavigne, J. -B.; Le Fustec,
   Y.; Le Poncin-Lafitte, C.; Lebreton, Y.; Leccia, S.; Leclerc, N.;
   Lecoeur-Taibi, I.; Lenhardt, H.; Leroux, F.; Liao, S.; Licata, E.;
   Lindstrom, H. E. P.; Lister, T. A.; Livanou, E.; Lobel, A.; Lopez, M.;
   Managau, S.; Mann, R. G.; Mantelet, G.; Marchal, O.; Marchant, J. M.;
   Marconi, M.; Marinoni, S.; Marschalko, G.; Marshall, D. J.; Martino,
   M.; Marton, G.; Mary, N.; Massari, D.; Matijevi?C, G.; Mazeh, T.;
   McMillan, P. J.; Messina, S.; Michalik, D.; Millar, N. R.; Molina,
   D.; Molinaro, R.; Molnar, L.; Montegrio, P.; Mor, R.; Morbidelli,
   R.; Morel, T.; Morris, D.; Mulone, A. F.; Muraveva, T.; Musella, I.;
   Nelemans, G.; Nicastro, L.; Noval, L.; O'Mullane, W.; Ordenovic, C.;
   Ordonez-Blanco, D.; Osborne, P.; Pagani, C.; Pagano, I.; Pailler, F.;
   Palacin, H.; Palaversa, L.; Panahi, A.; Pawlak, M.; Piersimoni, A. M.;
   Pineau, F. -X.; Plachy, E.; Plum, G.; Poggio, E.; Poujoulet, E.; Prsa,
   A.; Pulone, L.; Racero, E.; Ragaini, S.; Rambaux, N.; Ramos-Lerate,
   M.; Regibo, S.; Reyle, C.; Riclet, F.; Ripepi, V.; Riva, A.; Rivard,
   A.; Rixon, G.; Roegiers, T.; Roelens, M.; Romero-Gomez, M.; Rowell,
   N.; Royer, F.; Ruiz-Dern, L.; Sadowski, G.; Sagrista Selles, T.;
   Sahlmann, J.; Salgado, J.; Salguero, E.; Sanna, N.; Santana-Ros,
   T.; Sarasso, M.; Savietto, H.; Schultheis, M.; Sciacca, E.; Segol,
   M.; Segovia, J. C.; Segransan, D.; Shih, I. -C.; Siltala, L.; Silva,
   A. F.; Smart, R. L.; Smith, K. W.; Solano, E.; Solitro, F.; Sordo,
   R.; Soria Nieto, S.; Souchay, J.; Spagna, A.; Spoto, F.; Stampa,
   U.; Steele, I. A.; Steidelmueller, H.; Stephenson, C. A.; Stoev, H.;
   Suess, F. F.; Surdej, J.; Szabados, L.; Szegedi-Elek, E.; Tapiador,
   D.; Taris, F.; Tauran, G.; Taylor, M. B.; Teixeira, R.; Terrett, D.;
   Teyssandier, P.; Thuillot, W.; Titarenko, A.; Torra Clotet, F.; Turon,
   C.; Ulla, A.; Utrilla, E.; Uzzi, S.; Vaillant, M.; Valentini, G.;
   Valette, V.; van Elteren, A.; van Hemelryck, E.; Vaschetto, M.;
   Vecchiato, A.; Veljanoski, J.; Viala, Y.; Vicente, D.; Vogt, S.;
   von Essen, C.; Voss, H.; Votruba, V.; Voutsinas, S.; Walmsley, G.;
   Weiler, M.; Wertz, O.; Wevers, T.; Wyrzykowski, L.; Yoldas, A.; Zerjal,
   M.; Ziaeepour, H.; Zorec, J.; Zschocke, S.; Zucker, S.; Zurbach, C.;
   Zwitter, T.
2018yCat..36160010G    Altcode:
  We have determined the membership of 46 open clusters. For the nine
  clusters within 250pc we determined optimised parallaxes based on
  the combined information extracted from the measured parallax and
  proper motion values. These clusters are : in Tables A1a &amp; A3:
  alphaPer, Blanco1, ComaBer, Hyades, IC2391, IC2602, NGC2451A, Pleiades,
  Praesepe. The remaining 37 clusters are in Table A1b &amp; A4: Coll140,
  IC4651, IC4665, IC4725, IC4756, NGC0188, NGC0752, NGC0869, NGC0884,
  NGC1039, NGC1901, NGC2158, NGC2168, NGC2232, NGC2323, NGC2360, NGC2422,
  NGC2423, NGC2437, NGC2447, NGC2516, NGC2547, NGC2548, NGC2682, NGC3228,
  NGC3532, NGC6025, NGC6281, NGC6405, NGC6475, NGC6633, NGC6774, NGC6793,
  NGC7092, Stock2, Trump02, Trump10. <P />(4 data files).

---------------------------------------------------------
Title: Pulsation-induced atmospheric dynamics in M-type AGB
    stars. Effects on wind properties, photometric variations and near-IR
    CO line profiles
Authors: Liljegren, S.; Höfner, S.; Eriksson, K.; Nowotny, W.
2017A&A...606A...6L    Altcode: 2017arXiv170608332L
  Context. Wind-driving in asymptotic giant branch (AGB) stars is
  commonly attributed to a two-step process. First, matter in the stellar
  atmosphere is levitated by shock waves, induced by stellar pulsation,
  and second, this matter is accelerated by radiation pressure on dust,
  resulting in a wind. In dynamical atmosphere and wind models the
  effects of the stellar pulsation are often simulated by a simplistic
  prescription at the inner boundary. <BR /> Aims: We test a sample of
  dynamical models for M-type AGB stars, for which we kept the stellar
  parameters fixed to values characteristic of a typical Mira variable
  but varied the inner boundary condition. The aim was to evaluate the
  effect on the resulting atmosphere structure and wind properties. The
  results of the models are compared to observed mass-loss rates
  and wind velocities, photometry, and radial velocity curves, and to
  results from 1D radial pulsation models. The goal is to find boundary
  conditions which give realistic atmosphere and wind properties. <BR
  /> Methods: Dynamical atmosphere models are calculated, using the
  DARWIN code for different combinations of photospheric velocities and
  luminosity variations. The inner boundary is changed by introducing
  an offset between maximum expansion of the stellar surface and the
  luminosity and/or by using an asymmetric shape for the luminosity
  variation. Ninety-nine different combinations of theses two changes
  are tested. <BR /> Results: The model atmospheres are very sensitive to
  the inner boundary. Models that resulted in realistic wind velocities
  and mass-loss rates, when compared to observations, also produced
  realistic photometric variations. For the models to also reproduce the
  characteristic radial velocity curve present in Mira stars (derived
  from CO Δv = 3 lines), an overall phase shift of 0.2 between the maxima
  of the luminosity and radial variation had to be introduced. This is a
  larger phase shift than is found by 1D radial pulsation models. <BR />
  Conclusions: We find that a group of models with different boundary
  conditions (29 models, including the model with standard boundary
  conditions) results in realistic velocities and mass-loss rates, and
  in photometric variations. To achieve the correct line splitting time
  variation a phase shift is needed.

---------------------------------------------------------
Title: A grid of MARCS model atmospheres for late-type stars. II. S
    stars and their properties
Authors: Van Eck, Sophie; Neyskens, Pieter; Jorissen, Alain; Plez,
   Bertrand; Edvardsson, Bengt; Eriksson, Kjell; Gustafsson, Bengt;
   Jørgensen, Uffe Gråe; Nordlund, Åke
2017A&A...601A..10V    Altcode:
  S-type stars are late-type giants whose atmospheres are enriched in
  carbon and s-process elements because of either extrinsic pollution
  by a binary companion or intrinsic nucleosynthesis and dredge-up on
  the thermally-pulsing asymptotic giant branch. A grid of MARCS model
  atmospheres has been computed for S stars, covering the range 2700 ≤
  T<SUB>eff</SUB>(K) ≤ 4000, 0.50 ≤ C/O ≤ 0.99, 0 ≤ log g ≤ 5,
  [Fe/H] = 0., -0.5 dex, and [s/Fe] = 0, 1, and 2 dex (where the latter
  quantity refers to the global overabundance of s-process elements). The
  MARCS models make use of a new ZrO line list. Synthetic spectra
  computed from these models are used to derive photometric indices in
  the Johnson and Geneva systems, as well as TiO and ZrO band strengths. A
  method is proposed to select the model best matching any given S star,
  a non-trivial operation since the grid contains more than 3500 models
  covering a five-dimensional parameter space. The method is based on
  the comparison between observed and synthetic photometric indices and
  spectral band strengths, and has been applied on a vast subsample of
  the Henize sample of S stars. Our results confirm the old claim by
  Piccirillo (1980, MNRAS, 190, 441) that ZrO bands in warm S stars
  (T<SUB>eff</SUB>&gt;3200 K) are not caused by the C/O ratio being
  close to unity, as traditionally believed, but rather by some Zr
  overabundance. The TiO and ZrO band strengths, combined with V-K and
  J-K photometric indices, are used to select T<SUB>eff</SUB>, C/O, [Fe/H]
  and [s/Fe]. The Geneva U-B<SUB>1</SUB> and B<SUB>2</SUB>-V<SUB>1</SUB>
  indices (or any equivalent) are good at selecting the gravity. The
  defining spectral features of dwarf S stars are outlined, but none is
  found among the Henize S stars. More generally, it is found that, at
  T<SUB>eff</SUB> = 3200 K, a change of C/O from 0.5 to 0.99 has a strong
  impact on V-K (2 mag). Conversely, a range of 2 mag in V-K corresponds
  to a 200 K shift along the (T<SUB>eff</SUB>, V-K) relationship
  (for a fixed C/O value). Hence, the use of a (T<SUB>eff</SUB>, V-K)
  calibration established for M stars will yield large errors for S stars,
  so that a specific calibration must be used, as provided in the present
  paper. Using the atmospheric parameters derived by our method for the
  sample of Henize S stars, we show that the extrinsic-intrinsic dichotomy
  among S stars reveals itself very clearly as a bimodal distribution in
  the effective temperatures. Moreover, the increase of s-process element
  abundances with increasing C/O ratios and decreasing temperatures is
  apparent among intrinsic stars, confirming theoretical expectations. <P
  />Based on observations carried out at the European Southern Observatory
  (ESO, La Silla, Chile; program 58.E-0942), on the Swiss 70 cm telescope
  (La Silla, Chile) and on the Mercator telescope (La Palma, Spain).The
  MARCS S star model atmospheres will be archived on the MARCS website:
  <A href="http://marcs.astro.uu.se">http://marcs.astro.uu.se</A>Full
  Tables 2 and 3 are only available at the CDS via anonymous ftp to
  <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
  (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A10">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A10</A>

---------------------------------------------------------
Title: Aperture synthesis imaging of the carbon AGB star R
    Sculptoris. Detection of a complex structure and a dominating spot
    on the stellar disk
Authors: Wittkowski, M.; Hofmann, K. -H.; Höfner, S.; Le Bouquin,
   J. B.; Nowotny, W.; Paladini, C.; Young, J.; Berger, J. -P.; Brunner,
   M.; de Gregorio-Monsalvo, I.; Eriksson, K.; Hron, J.; Humphreys,
   E. M. L.; Lindqvist, M.; Maercker, M.; Mohamed, S.; Olofsson, H.;
   Ramstedt, S.; Weigelt, G.
2017A&A...601A...3W    Altcode: 2017arXiv170202574W
  <BR /> Aims: We present near-infrared interferometry of the carbon-rich
  asymptotic giant branch (AGB) star R Sculptoris (R Scl). <BR /> Methods:
  We employ medium spectral resolution K-band interferometry obtained with
  the instrument AMBER at the Very Large Telescope Interferometer (VLTI)
  and H-band low spectral resolution interferometric imaging observations
  obtained with the VLTI instrument PIONIER. We compare our data to a
  recent grid of dynamic atmosphere and wind models. We compare derived
  fundamental parameters to stellar evolution models. <BR /> Results:
  The visibility data indicate a broadly circular resolved stellar disk
  with a complex substructure. The observed AMBER squared visibility
  values show drops at the positions of CO and CN bands, indicating that
  these lines form in extended layers above the photosphere. The AMBER
  visibility values are best fit by a model without a wind. The PIONIER
  data are consistent with the same model. We obtain a Rosseland angular
  diameter of 8.9 ± 0.3 mas, corresponding to a Rosseland radius of 355
  ± 55 R<SUB>⊙</SUB>, an effective temperature of 2640 ± 80 K, and a
  luminosity of log L/L<SUB>⊙</SUB> = 3.74 ± 0.18. These parameters
  match evolutionary tracks of initial mass 1.5 ± 0.5 M<SUB>⊙</SUB>
  and current mass 1.3 ± 0.7 M<SUB>⊙</SUB>. The reconstructed PIONIER
  images exhibit a complex structure within the stellar disk including
  a dominant bright spot located at the western part of the stellar
  disk. The spot has an H-band peak intensity of 40% to 60% above the
  average intensity of the limb-darkening-corrected stellar disk. The
  contrast between the minimum and maximum intensity on the stellar
  disk is about 1:2.5. <BR /> Conclusions: Our observations are broadly
  consistent with predictions by dynamic atmosphere and wind models,
  although models with wind appear to have a circumstellar envelope
  that is too extended compared to our observations. The detected
  complex structure within the stellar disk is most likely caused by
  giant convection cells, resulting in large-scale shock fronts, and
  their effects on clumpy molecule and dust formation seen against
  the photosphere at distances of 2-3 stellar radii. <P />Based on
  observations made with the VLT Interferometry (VLTI) at Paranal
  Observatory under programme IDs 090.D-0136, 093.D-0015, 096.D-0720.

---------------------------------------------------------
Title: The adventure of carbon stars. Observations and modeling of
    a set of C-rich AGB stars
Authors: Rau, G.; Hron, J.; Paladini, C.; Aringer, B.; Eriksson, K.;
   Marigo, P.; Nowotny, W.; Grellmann, R.
2017A&A...600A..92R    Altcode: 2017arXiv170104331R
  Context. Modeling stellar atmospheres is a complex and intriguing
  task in modern astronomy. A systematic comparison of models with
  multi-technique observations is the only efficient way to constrain
  the models. <BR /> Aims: We intend to perform self-consistent
  modeling of the atmospheres of six carbon-rich AGB stars (<ASTROBJ>R
  Lep</ASTROBJ>, <ASTROBJ>R Vol</ASTROBJ>, <ASTROBJ>Y Pav</ASTROBJ>,
  <ASTROBJ>AQ Sgr</ASTROBJ>, <ASTROBJ>U Hya</ASTROBJ>, and <ASTROBJ>X
  TrA)</ASTROBJ> with the aim of enlarging the knowledge of the
  dynamic processes occurring in their atmospheres. <BR /> Methods:
  We used VLTI/MIDI interferometric observations, in combination with
  spectro-photometric data, and compared them with self-consistent,
  dynamic model atmospheres. <BR /> Results: We found that the models can
  reproduce spectral energy distribution (SED) data well at wavelengths
  longer than 1 μm, and the interferometric observations between 8 μm
  and 10 μm. Discrepancies observed at wavelengths shorter than 1 μm in
  the SED, and longer than 10 μm in the visibilities, could be due to a
  combination of data- and model-related effects. The models best fitting
  the Miras are significantly extended, and have a prominent shell-like
  structure. On the contrary, the models best fitting the non-Miras are
  more compact, showing lower average mass loss. The mass loss is of
  episodic or multi-periodic nature but causes the visual amplitudes to
  be notably larger than the observed ones. A number of stellar parameters
  were derived from the model fitting: T<SUB>Ross</SUB>, L<SUB>Ross</SUB>,
  M, C/O, and Ṁ. Our findings agree well with literature values within
  the uncertainties. T<SUB>Ross</SUB>, and L<SUB>Ross</SUB> are also in
  good agreement with the temperature derived from the angular diameter
  T(θ<SUB>(V-K)</SUB>) and the bolometric luminosity from the SED fitting
  L<SUB>bol</SUB>, except for AQ Sgr. The possible reasons are discussed
  in the text. Finally, θ<SUB>Ross</SUB> and θ<SUB>(V-K)</SUB> agree
  with one another better for the Miras than for the non-Miras targets,
  which is probably connected to the episodic nature of the latter
  models. We also located the stars in the H-R diagram, comparing them
  with evolutionary tracks. We found that the main derived properties (L,
  T<SUB>eff</SUB>, C/O ratios and stellar masses) from the model fitting
  are in good agreement with TP-AGB evolutionary calculations for carbon
  stars carried out with the COLIBRI code. <P />Based on observations made
  with ESO telescopes at La Silla Paranal Observatory under program IDs:
  090.D-0410, 086.D-899, 187.D-0924, 081.D-0021, 086.D-0899.

---------------------------------------------------------
Title: Abundances of disk and bulge giants from high-resolution
    optical spectra. I. O, Mg, Ca, and Ti in the solar neighborhood and
    Kepler field samples
Authors: Jönsson, H.; Ryde, N.; Nordlander, T.; Pehlivan Rhodin,
   A.; Hartman, H.; Jönsson, P.; Eriksson, K.
2017A&A...598A.100J    Altcode: 2016arXiv161105462J
  Context. The Galactic bulge is an intriguing and significant part
  of our Galaxy, but it is hard to observe because it is both distant
  and covered by dust in the disk. Therefore, there are not many
  high-resolution optical spectra of bulge stars with large wavelength
  coverage, whose determined abundances can be compared with nearby,
  similarly analyzed stellar samples. <BR /> Aims: We aim to determine
  the diagnostically important alpha elements of a sample of bulge
  giants using high-resolution optical spectra with large wavelength
  coverage. The abundances found are compared to similarly derived
  abundances from similar spectra of similar stars in the local thin and
  thick disks. In this first paper we focus on the solar neighborhood
  reference sample. <BR /> Methods: We used spectral synthesis to derive
  the stellar parameters as well as the elemental abundances of both the
  local and bulge samples of giants. We took special care to benchmark
  our method of determining stellar parameters against independent
  measurements of effective temperatures from angular diameter
  measurements and surface gravities from asteroseismology. <BR />
  Results: In this first paper we present the method used to determine
  the stellar parameters and elemental abundances, evaluate them, and
  present the results for our local disk sample of 291 giants. <BR />
  Conclusions: When comparing our determined spectroscopic temperatures
  to those derived from angular diameter measurements, we reproduce
  these with a systematic difference of +10 K and a standard deviation
  of 53 K. The spectroscopic gravities reproduce those determined from
  asteroseismology with a systematic offset of +0.10 dex and a standard
  deviation of 0.12 dex. When it comes to the abundance trends, our
  sample of local disk giants closely follows trends found in other works
  analyzing solar neighborhood dwarfs, showing that the much brighter
  giant stars are as good abundance probes as the often used dwarfs. <P
  />Based on observations made with the Nordic Optical Telescope (programs
  51-018 and 53-002), operated by the Nordic Optical Telescope Scientific
  Association at the Observatorio del Roque de los Muchachos, La Palma,
  Spain, of the Instituto de Astrofisica de Canarias, and on spectral
  data retrieved from PolarBase at Observatoire Midi Pyrénées.Full
  Tables A.1 and A.3 are only available at the CDS via anonymous ftp to
  <A href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
  (<A href="http://130.79.128.5">http://130.79.128.5</A>) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A100">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A100</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: A grid of MARCS model atmospheres
    for S stars (Van Eck+, 2017)
Authors: van Eck, S.; Neyskens, P.; Jorissen, A.; Plez, B.; Edvardsson,
   B.; Eriksson, K.; Gustafsson, B.; Jorgensen, U. G.; Nordlund, A.
2017yCat..36010010V    Altcode:
  Johnson and Geneva (G) photometric indices and band indices measured
  on the observed Henize S stars. <P />(3 data files).

---------------------------------------------------------
Title: Observational constraints for C-rich AGB stars
Authors: Rau, G.; Hron, J.; Paladini, C.; Aringer, B.; Marigo, P.;
   Eriksson, K.
2017MmSAI..88..455R    Altcode:
  We modeled the atmospheres of six carbon-rich Asymptotic Giant Branch
  stars (<ASTROBJ>R Lep</ASTROBJ>, <ASTROBJ>R Vol</ASTROBJ>, <ASTROBJ>Y
  Pav</ASTROBJ>, <ASTROBJ>AQ Sgr</ASTROBJ>, <ASTROBJ>U Hya</ASTROBJ>,
  and <ASTROBJ>X TrA)</ASTROBJ> using VLTI/MIDI interferometric
  observations, together with spectro-photometric data, we compared
  them with self-consistent, dynamic model atmospheres. The results show
  that the models can reproduce the Spectral Energy Distribution (SED)
  data well at wavelengths longer than 1 mu m, and the interferometric
  observations between 8 mu m and 10 mu m. We found differences at
  wavelengths shorter than 1 mu m in the SED, and longer than 10 mu m
  in the visibilities. The discrepancies observed can be explained in
  terms of a combination of data- and model-related reasons. We derived
  some stellar parameters, and our findings agree well with literature
  values within the uncertainties. Also, when comparing the location of
  the stars in the H-R diagram, with evolutionary tracks, the results
  show that the main derived properties (L, T<SUB>eff</SUB>, C/O ratios
  and stellar masses) from the model fitting are in good agreement with
  TP-AGB evolutionary calculations.

---------------------------------------------------------
Title: VizieR Online Data Catalog: Abundances of disk giants: O,
    Mg, Ca and Ti (Jonsson+, 2017)
Authors: Jonsson, H.; Ryde, N.; Nordlander, T.; Pehlivan Rhodin, A.;
   Hartman, H.; Jonsson, P.; Eriksson, K.
2016yCat..35980100J    Altcode:
  Spectroscopic stellar parameters and oxygen, magnesium, calcium, and
  titanium abundances for 291 local disk giants are presented. Spectra
  from observations with the spectrometer FIES at NOT, and from archives
  (FIES and PolarBase) are used. The FIES spectra have R=67000 and the
  ones from PolarBase have R=67000. In general most stars are very bright
  and have S/N around 100. <P />(2 data files).

---------------------------------------------------------
Title: Future Directions In The Study Of Asymptotic Giant Branch
    Stars With The James Webb Space Telescope
Authors: Hjort, Adam; Zackrisson, Erik; Eriksson, Kjell
2016csss.confE..40H    Altcode:
  In this study we present photometric predictions for C-type Asymptotic
  Giant Branch Stars (AGB) stars from Eriks- son et al. (2014) for the
  James Webb Space Telescope (JWST) and the Wide- eld Infrared Survey
  Explorer (WISE) instruments. The photometric predictions we have done
  are for JWST's general purpose wide-band lters on NIR- Cam and MIRI
  covering wavelengths of 0.7 — 21 microns. AGB stars contribute
  substantially to the integrated light of intermediate-age stellar
  popula- tions and is a substantial source of the metals (especially
  carbon) in galaxies. Studies of AGB stars are (among other reasons)
  important for the understanding of the chemical evolution and dust cycle
  of galaxies. Since the JWST is scheduled for launch in 2018 it should be
  a high priority to prepare observing strategies. With these predictions
  we hope it will be possible to optimize observing strategies of AGB
  stars and max- imize the science return of JWST. By testing our method
  on Whitelock et al. (2006) objects from the WISE catalog and comparing
  them with our photometric results based on Eriksson et al. (2014)
  we have been able to fit 20 objects with models. The photometric data
  set can be accessed at: http://www.astro.uu.se/AGBmodels/ABmags/

---------------------------------------------------------
Title: The Dynamic Atmospheres of Carbon Rich Giants: Constraining
    Models Via Interferometry
Authors: Rau, Gioia; Hron, Josef; Paladini, Claudia; Aringer, Bernard;
   Eriksson, Kjell; Marigo, Paola
2016csss.confE.111R    Altcode:
  Dynamic models for the atmospheres of C-rich Asymptotic Giant
  Branch stars are quite advanced and have been overall successful in
  reproducing spectroscopic and photometric observations. Interferometry
  provides independent information and is thus an important technique
  to study the atmospheric stratification and to further constrain the
  dynamic models. We observed a sample of six C-rich AGBs with the mid
  infrared interferometer VLTI/MIDI. These observations, combined with
  photometric and spectroscopic data from the literature, are compared
  with synthetic observables derived from dynamic model atmospheres (DMA,
  Eriksson et al. 2014). The SEDs can be reasonably well modelled and the
  interferometry supports the extended and multi-component structure of
  the atmospheres, but some differences remain. We discuss the possible
  reasons for these differences and we compare the stellar parameters
  derived from this comparison with stellar evolution models. Finally,
  we point out the high potential of MATISSE, the second generation VLTI
  instrument allowing interferometric imaging in the L, M, and N bands,
  for further progress in this field.

---------------------------------------------------------
Title: Modelling a Set of Carbon-Rich AGB Stars at High-Angular
    Resolution
Authors: Rau, Gioia; Hron, Josef; Paladini, Claudia; Aringer, Bernard;
   Eriksson, Kjell; Marigo, Paola; Nowotny, Walter; Grellmann, Rebekka
2016csss.confE.110R    Altcode:
  We compared spectro-photometric and interferometric observations
  of six carbon-rich AGB stars with a grid of self-consistentmodel
  atmospheres. The targets are: R Lep, R Vol, Y Pav, AQ Sgr, U Hya and
  X TrA. Please refer to the publication Rau et al. 2016(subm.) for
  further details on those findings.

---------------------------------------------------------
Title: Dust-driven winds of AGB stars: The critical interplay of
    atmospheric shocks and luminosity variations
Authors: Liljegren, S.; Höfner, S.; Nowotny, W.; Eriksson, K.
2016A&A...589A.130L    Altcode: 2016arXiv160306735L
  Context. Winds of AGB stars are thought to be driven by a combination
  of pulsation-induced shock waves and radiation pressure on dust. In
  dynamic atmosphere and wind models, the stellar pulsation is often
  simulated by prescribing a simple sinusoidal variation in velocity and
  luminosity at the inner boundary of the model atmosphere. <BR /> Aims:
  We experiment with different forms of the luminosity variation in order
  to assess the effects on the wind velocity and mass-loss rate, when
  progressing from the simple sinusoidal recipe towards more realistic
  descriptions. This will also give an indication of how robust the
  wind properties derived from the dynamic atmosphere models are. <BR />
  Methods: Using state-of-the-art dynamical models of C-rich AGB stars,
  a range of different asymmetric shapes of the luminosity variation
  and a range of phase shifts of the luminosity variation relative to
  the radial variation are tested. These tests are performed on two
  stellar atmosphere models. The first model has dust condensation and,
  as a consequence, a stellar wind is triggered, while the second model
  lacks both dust and wind. <BR /> Results: The first model with dust and
  stellar wind is very sensitive to moderate changes in the luminosity
  variation. There is a complex relationship between the luminosity
  minimum, and dust condensation: changing the phase corresponding to
  minimum luminosity can either increase or decrease mass-loss rate and
  wind velocity. The luminosity maximum dominates the radiative pressure
  on the dust, which in turn, is important for driving the wind. An
  earlier occurrence of the maximum, with respect to the propagation of
  the pulsation-induced shock wave, then increases the wind velocity,
  while a later occurrence leads to a decrease. These effects of changed
  luminosity variation are coupled with the dust formation. In contrast
  there is very little change to the structure of the model without
  dust. <BR /> Conclusions: Changing the luminosity variation, both
  by introducing a phase shift and by modifying the shape, influences
  wind velocity and the mass-loss rate. To improve wind models it would
  probably be desirable to extract boundary conditions from 3D dynamical
  interior models or stellar pulsation models.

---------------------------------------------------------
Title: The Carbon Stars Adventure
Authors: Rau, Gioia; Paladini, C.; Hron, J.; Aringer, B.; Eriksson,
   K.; Groenewegen, M. A. T.; Nowotny, W.
2016IAUFM..29B.160R    Altcode:
  We compare in a systematic way spectrometric, photometric and
  mid-infrared (VLTI/MIDI) interferometric measurements with different
  types of model atmospheres. Self-consistent dynamic model atmospheres
  in particular were used to interpret in a consistent way the dynamic
  behavior of gas and dust. The results underline how the joint use
  of different kind of observations, as photometry, spectroscopy and
  interferometry, is essential to understand the atmospheres of pulsating
  C-rich AGB stars. The sample of C-rich stars discussed in this work
  provides crucial constraints for the atmospheric structure.

---------------------------------------------------------
Title: A New Library of Synthetic Spectra and Photometry for Evolved
    C Stars
Authors: Eriksson, K.; Nowotny, W.; Höfner, S.; Aringer, B.
2015ASPC..497..111E    Altcode:
  We present a library of synthetic spectra and photometry calculated
  on the basis of a grid of atmosphere and wind models for carbon-rich,
  pulsating AGB stars. The spectra cover the range between 0.35 and 25
  μm with a spectral resolution of R = 200. The corresponding photometric
  variations during several pulsation periods were computed for standard
  broadband filters in the visual and near-infrared.

---------------------------------------------------------
Title: Evolved Stars with Complex Atmospheres - the High Spectral
    Resolution, mid-IR View
Authors: Ryde, N.; Lambert, J.; Richter, M. J.; Josselin, E.; Harper,
   G. M.; Eriksson, K.; Boogert, A.; DeWitt, C.; Encrenaz, T.; Greathouse,
   T.; Jaffe, D.; Kulas, K.; McKelvey, M.; Najita, J.; Vacca, W.
2015ASPC..497...67R    Altcode: 2014arXiv1408.6055R
  The physical structures of the outer atmospheres of red giants are not
  known. They are certainly complex, and a range of recent observations
  are showing that we need to embrace non-classical model atmospheres to
  interpret these regions. This region's properties are of importance,
  not the least for an understanding of the mass-loss mechanism for these
  stars. Here we present observational constraints on the outer regions
  of red giants, based on mid-IR, high spectral resolution spectra. We
  also discuss possible non-LTE effects and highlight a new non-LTE
  code that will be used to analyse the spectra of these atmospheric
  layers. We conclude by mentioning our new SOFIA/EXES observations
  of red giants at 6 μm, where the vibration-rotation lines of water
  vapour can be detected and spectrally resolved for the first time.

---------------------------------------------------------
Title: Into the Modelling of RU Vir
Authors: Rau, G.; Hron, J.; Paladini, C.; Eriksson, K.; Aringer, B.;
   Groenewegen, M. A. T.; Mečina, M.
2015ASPC..497..137R    Altcode:
  We present an attempt to model the atmosphere of the carbon-rich Mira
  star RU Vir, using different techniques including spectroscopy,
  photometry, and interferometry. A radiative transfer code and
  hydrostatic model atmospheres were used for a preliminary study. To
  investigate the dynamic processes happening in RU Vir, dynamic model
  atmospheres were compared to new MIDI/VLTI observations obtained in
  April 2014, and SiC opacities were added.

---------------------------------------------------------
Title: Winds of AGB Stars - The Role of Stellar Pulsation
Authors: Liljegren, S.; Höfner, S.; Eriksson, K.
2015ASPC..497..127L    Altcode:
  Changing the stellar pulsation properties has large impact on the
  behavior of the atmosphere of C-type AGB stars. This relationship
  is examined.

---------------------------------------------------------
Title: Exploring Mass-Loss in M-type AGB Stars
Authors: Bladh, S.; Höfner, S.; Aringer, B.; Eriksson, K.
2015ASPC..497..345B    Altcode:
  Stellar winds observed in asymptotic giant branch (AGB) stars are
  usually attributed to a combination of stellar pulsations and radiation
  pressure on dust. Strong candidates for wind-driving dust species in
  M-type AGB stars are magnesium silicates (Mg<SUB>2</SUB>SiO<SUB>4</SUB>
  and MgSiO<SUB>3</SUB>). Such grains can form close to the stellar
  surface; they consist of abundant materials and, if they grow to
  sizes comparable to the wavelength of the stellar flux maximum,
  they experience strong acceleration by photon scattering. Here we
  present results from an extensive set of time-dependent wind models
  for M-type AGB stars with a detailed description for the growth
  of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains. We show that these models
  reproduce observed mass-loss rates and wind velocities, as well as
  visual and near-IR photometry. However, the current models do not
  show the characteristic silicate features at 10 and 18 μm, due to a
  rapidly falling temperature of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains
  in the wind. Including a small amount of Fe in the grains further out
  in the circumstellar envelope will increase the grain temperature and
  result in pronounced silicate features, without significantly affecting
  the photometry in the visual and near-IR.

---------------------------------------------------------
Title: Exploring wind-driving dust species in cool luminous
giants. III. Wind models for M-type AGB stars: dynamic and photometric
    properties
Authors: Bladh, S.; Höfner, S.; Aringer, B.; Eriksson, K.
2015A&A...575A.105B    Altcode: 2015arXiv150200032B
  Context. Stellar winds observed in asymptotic giant branch (AGB)
  stars are usually attributed to a combination of stellar pulsations
  and radiation pressure on dust. Shock waves triggered by pulsations
  propagate through the atmosphere, compressing the gas and lifting
  it to cooler regions which creates favourable conditions for
  grain growth. If sufficient radiative acceleration is exerted
  on the newly formed grains through absorption or scattering of
  stellar photons, an outflow can be triggered. Strong candidates for
  wind-driving dust species in M-type AGB stars are magnesium silicates
  (Mg<SUB>2</SUB>SiO<SUB>4</SUB> and MgSiO<SUB>3</SUB>). Such grains
  can form close to the stellar surface, they consist of abundant
  materials and, if they grow to sizes comparable to the wavelength of
  the stellar flux maximum, they experience strong acceleration by photon
  scattering. <BR /> Aims: The purpose of this study is to investigate
  if photon scattering on Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains can
  produce realistic outflows for a wide range of stellar parameters
  in M-type AGB stars. <BR /> Methods: We use a frequency-dependent
  radiation-hydrodynamics code with a detailed description for the
  growth of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains to calculate the
  first extensive set of time-dependent wind models for M-type AGB
  stars. This set includes 139 solar-mass models, with three different
  luminosities (5000 L<SUB>⊙</SUB>, 7000 L<SUB>⊙</SUB>, and 10 000
  L<SUB>⊙</SUB>) and effective temperatures ranging from 2600 K to
  3200 K. The resulting wind properties, visual and near-IR photometry
  and mid-IR spectra are compared with observations. <BR /> Results:
  We show that the models can produce outflows for a wide range of
  stellar parameters. We also demonstrate that they reproduce observed
  mass-loss rates and wind velocities, as well as visual and near-IR
  photometry. However, the current models do not show the characteristic
  silicate features at 10 and 18 μm as a result of the cool temperature
  of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains in the wind. Including a small
  amount of Fe in the grains further out in the circumstellar envelope
  will increase the grain temperature and result in pronounced silicate
  features, without significantly affecting the photometry in the visual
  and near-IR wavelength regions. <BR /> Conclusions: Outflows driven by
  photon scattering on Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains are a viable
  wind scenario for M-type AGB stars, given the success of the current
  models in reproducing observed mass-loss rates, wind velocities, and
  photometry. Both synthetic and observed photometry suggest that the
  dusty envelopes of M-type AGB stars are quite transparent at visual
  and near-IR wavelengths, otherwise the variations in visual flux would
  not be dominated by molecular features.

---------------------------------------------------------
Title: Systematic trend of water vapour absorption in red giant
    atmospheres revealed by high resolution TEXES 12 μm spectra
Authors: Ryde, N.; Lambert, J.; Farzone, M.; Richter, M. J.; Josselin,
   E.; Harper, G. M.; Eriksson, K.; Greathouse, T. K.
2015A&A...573A..28R    Altcode: 2014arXiv1410.3999R
  Context. The structures of the outer atmospheres of red giants are very
  complex. Recent interpretations of a range of different observations
  have led to contradictory views of these regions. It is clear, however,
  that classical model photospheres are inadequate to describe the
  nature of the outer atmospheres. The notion of large optically thick
  molecular spheres around the stars (MOLspheres) has been invoked in
  order to explain spectro-interferometric observations and low- and
  high-resolution spectra. On the other hand high-resolution spectra in
  the mid-IR do not easily fit into this picture because they rule out
  any large sphere of water vapour in LTE surrounding red giants. <BR />
  Aims: In order to approach a unified scenario for these outer regions
  of red giants, more empirical evidence from different diagnostics are
  needed. Our aim here is to investigate high-resolution, mid-IR spectra
  for a range of red giants, spanning spectral types from early K to mid
  M. We want to study how the pure rotational lines of water vapour change
  with effective temperature, and whether we can find common properties
  that can put new constraints on the modelling of these regions,
  so that we can gain new insights. <BR /> Methods: We have recorded
  mid-IR spectra at 12.2 - 12.4 μm at high spectral resolution of ten
  well-studied bright red giants, with TEXES mounted on the IRTF on Mauna
  Kea. These stars span effective temperatures from 3450 K to 4850 K. <BR
  /> Results: We find that all red giants in our study cooler than 4300 K,
  spanning a wide range of effective temperatures (down to 3450 K), show
  water absorption lines stronger than expected and none are detected
  in emission, in line with what has been previously observed for a few
  stars. The strengths of the lines vary smoothly with spectral type. We
  identify several spectral features in the wavelength region that are
  undoubtedly formed in the photosphere. From a study of water-line
  ratios of the stars, we find that the excitation temperatures, in the
  line-forming regions, are several hundred Kelvin lower than expected
  from a classical photospheric model. <BR /> Conclusions: All stars in
  our sample show several photospheric features in their 12 μm spectra,
  which can be modelled with a classical model photosphere. However, in
  all stars showing water-vapour lines (stars cooler than ~4300 K), the
  water lines are found to be much deeper than expected. The line ratios
  of these pure-rotational lines reveal low excitation temperatures. This
  could either be due to lower temperatures than expected in the outer
  regions of the photospheres caused by for example extra cooling,
  or due to non-LTE level populations, affecting the source function
  and line opacities, but this needs further investigation. We have
  demonstrated that these diagnostically interesting water lines are
  a general feature of red giants across spectral types, and we argue
  for a general explanation of their formation rather than explanations
  requiring specific properties, such as dust. Since the water lines are
  neither weak (filled in by emission) nor do they appear in emission,
  as predicted by LTE MOLsphere models in their simplest forms, the
  evidence of the existence of such large optically-thick, molecular
  spheres enshrouding the stars is weakened. It is still a challenge
  to find a unifying picture of the outer regions of the atmospheres
  of red giants, but we have presented new empirical evidence that
  needs to be taken into account and explained in any model of
  these regions. <P />Table 4 is available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201424851/olm">http://www.aanda.org</A>

---------------------------------------------------------
Title: The Hamburg/ESO R-process Enhanced Star survey (HERES). X. HE
    2252-4225, one more r-process enhanced and actinide-boost halo star
Authors: Mashonkina, L.; Christlieb, N.; Eriksson, K.
2014A&A...569A..43M    Altcode: 2014arXiv1407.5379M
  Context. Studies of the r-process enhanced stars are important for
  understanding the nature and origin of the r-process better. <BR />
  Aims: We present a detailed abundance analysis of a very metal-poor
  giant star discovered in the HERES project, HE 2252-4225, which
  exhibits overabundances of the r-process elements with [r/Fe]
  = +0.80. <BR /> Methods: We determined the stellar atmosphere
  parameters, T<SUB>eff</SUB> = 4710 K, log g = 1.65, and [ Fe/H ] =
  -2.63, and chemical abundances by analysing the high-quality VLT/UVES
  spectra. The surface gravity was calculated from the non-local
  thermodynamic equilibrium (NLTE) ionisation balance between Fe i
  and Fe ii. <BR /> Results: Accurate abundances for a total of 38
  elements, including 22 neutron-capture elements beyond Sr and up
  to Th, were determined in HE 2252-4225. For every chemical species,
  the dispersion in the single line measurements around the mean does
  not exceed 0.12 dex. This object is deficient in carbon, as expected
  for a giant star with T<SUB>eff</SUB> &lt; 4800 K. The stellar Na-Zn
  abundances are well fitted by the yields of a single supernova of
  14.4 M<SUB>⊙</SUB>. For the neutron-capture elements in the Sr-Ru,
  Ba-Yb, and Os-Ir regions, the abundance pattern of HE 2252-4225 is in
  excellent agreement with the average abundance pattern of the strongly
  r-process enhanced stars CS 22892-052, CS 31082-001, HE 1219-0312,
  and HE 1523-091. This suggests a common origin of the first, second,
  and third r-process peak elements in HE 2252-4225 in the classical
  r-process. We tested the solar r-process pattern based on the most
  recent s-process calculations of Bisterzo, Travaglio, Gallino, Wiescher,
  and Käppeler and found that elements in the range from Ba to Ir match
  it very well. No firm conclusion can be drawn about the relationship
  between the first neutron-capture peak elements, Sr to Ru, in HE
  2252-4225 and the solar r-process, owing to the uncertainty in the
  solar r-process. The investigated star has an anomalously high Th/Eu
  abundance ratio, so that radioactive dating results in a stellar age
  of τ = 1.5 ± 1.5 Gyr that is not expected for a very metal-poor
  halo star. <P />Based on observations collected at the European
  Southern Observatory, Paranal, Chile (Proposal numbers 170.D-0010, and
  280.D-5011).Table 3 is only available at the CDS via anonymous ftp to <A
  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
  (ftp://130.79.128.5) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/569/A43">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/569/A43</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: HE 2252-4225 abundance analysis
    (Mashonkina+, 2014)
Authors: Mashonkina, L.; Christlieb, N.; Eriksson, K.
2014yCat..35690043M    Altcode: 2014yCat..35699043M
  HE 2252-4225 was identified as a candidate metal-poor star in the
  Hamburg/ESO Survey (HES), and it was included in the target list of the
  Hamburg/ESO R-process-Enhanced Star survey (HERES, Christlieb et al.,
  Paper I, 2004A&amp;A...428.1027C). Stellar parameters, Teff=4708+-100K,
  logg=1.53+/-0.24, and [Fe/H]=-2.83+/-0.12, were first determined
  by Barklem et al. (Paper II. Cat. J/A+A/439/129) based on automated
  abundance analysis of high-resolution "snapshot" spectra. The photometry
  was taken from Beers et al. (2007, Cat. J/ApJS/168/128). High-quality
  spectra of this star was acquired during May-September 2005 with the
  VLT and UVES in dichroic mode. The BLUE390+RED580 (9h total integration
  time) and BLUE437+RED860 (10h) standard settings were employed to
  ensure a wide wavelength coverage. <P />(2 data files).

---------------------------------------------------------
Title: Synthetic photometry for carbon-rich giants. IV. An extensive
    grid of dynamic atmosphere and wind models
Authors: Eriksson, K.; Nowotny, W.; Höfner, S.; Aringer, B.;
   Wachter, A.
2014A&A...566A..95E    Altcode: 2014arXiv1404.7515E
  Context. The evolution and spectral properties of stars on the
  asymptotic giant branch (AGB) are significantly affected by mass
  loss through dusty stellar winds. Dynamic atmosphere and wind
  models are an essential tool for studying these evolved stars, both
  individually and as members of stellar populations, to understand
  their contribution to the integrated light and chemical evolution
  of galaxies. <BR /> Aims: This paper is part of a series with the
  purpose of testing state-of-the-art atmosphere and wind models of
  C-type AGB stars against observations, and making them available
  to the community for use in various theoretical and observational
  studies. <BR /> Methods: We have computed low-resolution spectra and
  photometry (in the wavelength range 0.35-25 μm) for a grid of 540
  dynamic models with stellar parameters typical of solar-metallicity
  C-rich AGB stars and with a range of pulsation amplitudes. The models
  cover the dynamic atmosphere and dusty outflow (if present), assuming
  spherical symmetry, and taking opacities of gas-phase species and dust
  grains consistently into account. To characterize the time-dependent
  dynamic and photometric behaviour of the models in a concise way we
  defined a number of classes for models with and without winds. <BR
  /> Results: Comparisons with observed data in general show a quite
  satisfactory agreement for example regarding mass-loss rates vs. (J -
  K) colours or K magnitudes vs. (J - K) colours. Some exceptions from
  the good overall agreement, however, are found and attributed to
  the range of input parameters (e.g. relatively high carbon excesses)
  or intrinsic model assumptions (e.g. small particle limit for grain
  opacities). <BR /> Conclusions: While current results indicate
  that some changes in model assumptions and parameter ranges should
  be made in the future to bring certain synthetic observables into
  better agreement with observations, it seems unlikely that these
  pending improvements will significantly affect the mass-loss rates
  of the models. <P />Appendices are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201323241/olm">http://www.aanda.org</A>Table
  B.1, photometry, and spectra for all snapshots are available from <A
  href="http://www.astro.uu.se/AGBmodels">http://www.astro.uu.se/AGBmodels</A>
  and also at the CDS via anonymous ftp to <A
  href="http://cdsarc.u-strasbg.fr">http://cdsarc.u-strasbg.fr</A>
  (ftp://130.79.128.5) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A95">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A95</A>

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Title: Chemical evolution of fluorine in the bulge. High-resolution
    K-band spectra of giants in three fields
Authors: Jönsson, H.; Ryde, N.; Harper, G. M.; Cunha, K.; Schultheis,
   M.; Eriksson, K.; Kobayashi, C.; Smith, V. V.; Zoccali, M.
2014A&A...564A.122J    Altcode: 2014arXiv1403.2594J
  Context. Possible main formation sites of fluorine in the Universe
  include asymptotic giant branch (AGB) stars, the ν-process in Type II
  supernova, and/or Wolf-Rayet stars. The importance of the Wolf-Rayet
  stars has theoretically been questioned and they are probably not
  needed in modeling the chemical evolution of fluorine in the solar
  neighborhood. It has, however, been suggested that Wolf-Rayet stars
  are indeed needed to explain the chemical evolution of fluorine in the
  bulge. The molecular spectral data, needed to determine the fluorine
  abundance, of the often used HF-molecule has not been presented
  in a complete and consistent way and has recently been debated in
  the literature. <BR /> Aims: We intend to determine the trend of
  the fluorine-oxygen abundance ratio as a function of a metallicity
  indicator in the bulge to investigate the possible contribution from
  Wolf-Rayet stars. Additionally, we present here a consistent HF line
  list for the K- and L-bands including the often used 23 358.33 Å
  line. <BR /> Methods: High-resolution near-infrared spectra of eight
  K giants were recorded using the spectrograph CRIRES mounted at the
  VLT. A standard setting was used that covered the HF molecular line at
  23 358.33 Å. The fluorine abundances were determined using spectral
  fitting. We also re-analyzed five previously published bulge giants
  observed with the Phoenix spectrograph on Gemini using our new HF
  molecular data. <BR /> Results: We find that the fluorine-oxygen
  abundance in the bulge probably cannot be explained with chemical
  evolution models that only include AGB stars and the ν-process
  in supernovae Type II, that is a significant amount of fluorine
  production in Wolf-Rayet stars is most likely needed to explain the
  fluorine abundance in the bulge. For the HF line data, we find that a
  possible reason for the inconsistencies in the literature, where two
  different excitation energies were used, is two different definitions
  of the zero-point energy for the HF molecule and therefore also two
  accompanying different dissociation energies. Both line lists are
  correct as long as the corresponding consistent partition function is
  used in the spectral synthesis. However, we suspect this has not been
  the case in several earlier works, which led to fluorine abundances
  ~0.3 dex too high. We present a line list for the K- and L-bands and an
  accompanying partition function. <P />Based on observations collected
  at the European Southern Observatory, Chile (ESO programs 71.B-0617(A),
  073.B0074(A), and 079.B-0338(A)) and observations obtained at the Gemini
  Observatory, which is operated by the Association of Universities
  for Research in Astronomy, Inc., under a cooperative agreement with
  the NSF on behalf of the Gemini partnership: the National Science
  Foundation (United States), the National Research Council (Canada),
  CONICYT (Chile), the Australian Research Council (Australia), CNPq
  (Brazil), and CONICRT (Argentina), as program GS-2004A-Q-20.Figure
  4 and Tables 5 and 6 are available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201423597/olm">http://www.aanda.org</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: C-rich giants synthetic
    spectrophotometry. IV (Eriksson+, 2014)
Authors: Eriksson, K.; Nowotny, W.; Hofner, S.; Aringer, B.;
   Wachter, A.
2014yCat..35660095E    Altcode: 2014yCat..35669095E
  For each model there are a number of files with photometry data,
  one for each epoch, and there are up to five different epochs per
  model, typically two epochs. Each of these files contains photometry
  data for at least two pulsation periods. <P />The files are in the
  following format: <P />Byte-by-byte Description of file: DMAfilters/*/*
  ------------------------------------------------------------------------------
  Bytes Format Units Label Explanations
  ------------------------------------------------------------------------------
  3- 8 F6.3 mag Bmag Synthetic Johnson-Cousins B magnitude (1) 11-
  16 F6.3 mag Vmag Synthetic Johnson-Cousins V magnitude (1) 19-
  24 F6.3 mag Rmag Synthetic Johnson-Cousins Rc magnitude (1) 27-
  32 F6.3 mag Imag Synthetic Johnson-Cousins I magnitude (1) 35-
  40 F6.3 mag Jmag Synthetic Johnson-Glass J magnitude (1) 43- 48
  F6.3 mag Hmag Synthetic Johnson-Glass H magnitude (1) 51- 56 F6.3
  mag Kmag Synthetic Johnson-Glass K magnitude (1) 58- 64 F7.3 mag
  Lmag Synthetic Johnson-Glass L magnitude (1) 66- 72 F7.3 mag L'mag
  Synthetic Johnson-Glass L' magnitude (1) 74- 80 F7.3 mag Mmag Synthetic
  Johnson-Glass M magnitude (1) 83- 88 F6.3 mag J2mag Synthetic 2MASS
  J magnitude 91- 96 F6.3 mag H2mag Synthetic 2MASS H magnitude 99-104
  F6.3 mag Ks2mag Synthetic 2MASS Ks magnitude 107-112 F6.3 --- Phase
  Pulsational phase, with luminosity maxima at 0.0, 1.0 etc. 115-120
  I6 --- Snapshot Snapshot identification number (timestep number)
  ------------------------------------------------------------------------------
  Note (1): B,V,R,I; see Bessell 1990PASP..102.1181B),
  and in the Johnson-Glass (J, H, K, L, L',
  M; see Bessell and Brett 1988PASP..100.1134B)
  ------------------------------------------------------------------------------
  <P />(4 data files).

---------------------------------------------------------
Title: Detailed near-IR stellar abundances of red giants in the Bulge
Authors: Ryde, N.; Jönsson, H.; Schultheis, M.; Matteucci, F.;
   Harper, G. M.; Cunha, K.; Eriksson, K.; Kobayashi, C.; Smith, V. V.;
   Zoccali, M.
2014fegb.confE..12R    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Fundamental parameters of 16 late-type stars derived from
    their angular diameter measured with VLTI/AMBER
Authors: Cruzalèbes, P.; Jorissen, A.; Rabbia, Y.; Sacuto, S.;
   Chiavassa, A.; Pasquato, E.; Plez, B.; Eriksson, K.; Spang, A.;
   Chesneau, O.
2013MNRAS.434..437C    Altcode: 2013arXiv1306.3288C; 2013MNRAS.tmp.1678C
  Thanks to their large angular dimension and brightness, red giants
  and supergiants are privileged targets for optical long-baseline
  interferometers. 16 red giants and supergiants have been observed
  with the VLTI/AMBER facility over a 2-year period, at medium spectral
  resolution (R=1500) in the K band. The limb-darkened angular diameters
  are derived from fits of stellar atmospheric models on the visibility
  and the triple product data. The angular diameters do not show any
  significant temporal variation, except for one target: TX Psc, which
  shows a variation of 4 per cent using visibility data. For the eight
  targets previously measured by long-baseline interferometry (LBI)
  in the same spectral range, the difference between our diameters and
  the literature values is less than 5 per cent, except for TX Psc,
  which shows a difference of 11 per cent. For the eight other targets,
  the present angular diameters are the first measured from LBI. Angular
  diameters are then used to determine several fundamental stellar
  parameters, and to locate these targets in the Hertzsprung-Russell
  diagram (HRD). Except for the enigmatic Tc-poor low-mass carbon star W
  Ori, the location of Tc-rich stars in the HRD matches remarkably well
  the thermally-pulsating asymptotic giant branch, as it is predicted
  by the stellar evolution models. For pulsating stars with periods
  available, we compute the pulsation constant and locate the stars along
  the various sequences in the period-luminosity diagram. We confirm
  the increase in mass along the pulsation sequences, as predicted by
  theory, except for W Ori which, despite being less massive, appears
  to have a longer period than T Cet along the first-overtone sequence.

---------------------------------------------------------
Title: Exploring wind-driving dust species in cool luminous
    giants. II. Constraints from photometry of M-type AGB stars
Authors: Bladh, S.; Höfner, S.; Nowotny, W.; Aringer, B.; Eriksson, K.
2013A&A...553A..20B    Altcode: 2013arXiv1302.6572B
  Context. The heavy mass loss observed in evolved asymptotic giant
  branch (AGB) stars is usually attributed to a two-stage process:
  atmospheric levitation by pulsation-induced shock waves, followed
  by radiative acceleration of newly formed dust grains. The dust
  transfers momentum to the surrounding gas through collisions and
  thereby triggers a general outflow. Radiation-hydrodynamical models
  of M-type AGB stars suggest that these winds can be driven by photon
  scattering - in contrast to absorption - on Fe-free silicate grains
  of sizes 0.1-1 μm. <BR /> Aims: In this paper we study photometric
  constraints for wind-driving dust species in M-type AGB stars, as part
  of an ongoing effort to identify likely candidates among the grain
  materials observed in circumstellar envelopes. <BR /> Methods: To
  investigate the scenario of stellar winds driven by photon scattering
  on dust, and to explore how different optical and chemical properties
  of wind-driving dust species affect photometry we focus on two sets of
  dynamical models atmospheres: (i) models using a detailed description
  for the growth of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains, taking into
  account both scattering and absorption cross-sections when calculating
  the radiative acceleration; and (ii) models using a parameterized dust
  description, constructed to represent different chemical and optical
  dust properties. By comparing synthetic photometry from these two
  sets of models to observations of M-type AGB stars we can provide
  constraints on the properties of wind-driving dust species. <BR />
  Results: Photometry from wind models with a detailed description for
  the growth of Mg<SUB>2</SUB>SiO<SUB>4</SUB> grains reproduces well
  both the values and the time-dependent behavior of observations of
  M-type AGB stars, providing further support for the scenario of winds
  driven by photon scattering on dust. The photometry from the models
  with a parameterized dust description suggests that wind-drivers need
  to have a low absorption cross-section in the visual and near-IR to
  reproduce the time-dependent behavior, i.e. small variations in (J - K)
  and spanning a larger range in (V - K). This places constraints on the
  optical and chemical properties of the wind-driving dust species. <BR />
  Conclusions: To reproduce the observed photometric variations in (V -
  K) and (J - K) both detailed and parameterized models suggest that the
  wind-driving dust materials have to be quite transparent in the visual
  and near-IR. Consequently, strong candidates for outflows driven by
  photon scattering on dust grains are Mg<SUB>2</SUB>SiO<SUB>4</SUB>,
  MgSiO<SUB>3</SUB>, and potentially SiO<SUB>2</SUB>.

---------------------------------------------------------
Title: What is the Origin of the Water Vapour Signatures in Red
    Giant Stars?
Authors: Farzone, M.; Ryde, N.; Harper, G. M.; Lambert, J.; Josselin,
   E.; Richter, M. J.; Eriksson, K.
2013EAS....60..155F    Altcode:
  We investigate the occurrence of water vapour signatures in a total of
  10 red giants in the solar neighbourhood at mid-infrared wavelengths
  (12 μm). With the use of high resolution spectra from TEXES and
  synthesized spectra based on MARCS model atmospheres, we analyse the
  differences and discuss plausible causes. These include abundance
  adjustments, the addition of non-photospheric components (MOLspheres)
  and a different temperature profile.

---------------------------------------------------------
Title: Synthetic photometry for carbon-rich giants. III. Tracing
    the sequence of mass-losing galactic C-type Miras
Authors: Nowotny, W.; Aringer, B.; Höfner, S.; Eriksson, K.
2013A&A...552A..20N    Altcode: 2013arXiv1302.3715N
  Late-type giant stars in the evolutionary stage of the asymptotic giant
  branch increasingly lose mass via comparatively slow but dense stellar
  winds. Not only do these evolved red giants contribute in this way to
  the enrichment of the surrounding interstellar medium, but the outflows
  also have a substantial influence on the spectro-photometric appearance
  of such objects. In the case of carbon-rich atmospheric chemistries,
  the developing cool circumstellar envelopes contain dust grains mainly
  composed of amorphous carbon. With increasing mass-loss rates, this
  leads to more and more pronounced circumstellar reddening. With the
  help of model calculations we aim at reproducing the observational
  photometric findings for a large sample of well-characterised galactic
  C-type Mira variables losing mass at different rates. We used dynamic
  model atmospheres, describing the outer layers of C-rich Miras,
  which are severly affected by dynamic effects. Based on the resulting
  structures and under the assumptions of chemical equilibrium as well as
  LTE, we computed synthetic spectra and synthetic broad-band photometry
  (Johnson-Cousins-Glass BVRIJHKL'M). A set of five representative models
  with different stellar parameters describes a sequence from less to
  more evolved objects with steadily increasing mass-loss rates. This
  allowed us to study the significant influence of circumstellar dust on
  the spectral energy distributions and the (amplitudes of) lightcurves
  in different filters. We tested the photometric properties (mean
  NIR magnitudes, colours, and amplitudes) and other characteristics
  of the models (mass-loss rates, periods, and bolometric corrections)
  by comparing these with the corresponding observational data adopted
  from the literature. Using different kinds of diagrams we illustrate
  where the models are located in a supposed evolutionary sequence
  defined by observed C-type Mira samples. Based on comparisons of
  galactic targets with empirical relations derived for C stars in the
  Large Magellanic Cloud we discuss the relevance of metallicity and
  excess carbon (C-O) for the development of dust-driven winds. Having
  investigated the dynamic model atmospheres from different (mainly
  photometric) perspectives, we conclude that our modelling approach
  (meaning the combination of numerical method and a suitable choice of
  model parameters) is able to describe C-rich long-period variables over
  a wide range of mass-loss rates, i.e., from moderately pulsating objects
  without any dusty wind to highly dust-enshrouded Carbon Miras. Thus,
  we can trace the observed sequence of C-type Miras, which is mainly
  determined by the mass loss. <P />Appendices are available in electronic
  form at <A href="http://www.aanda.org">http://www.aanda.org</A>

---------------------------------------------------------
Title: The wind of the M-type AGB star <ASTROBJ>RT Virginis</ASTROBJ>
    probed by VLTI/MIDI
Authors: Sacuto, S.; Ramstedt, S.; Höfner, S.; Olofsson, H.; Bladh,
   S.; Eriksson, K.; Aringer, B.; Klotz, D.; Maercker, M.
2013A&A...551A..72S    Altcode: 2013arXiv1301.5872S
  <BR /> Aims: We study the circumstellar environment of the M-type
  AGB star <ASTROBJ>RT Vir</ASTROBJ> using mid-infrared high spatial
  resolution observations from the ESO-VLTI focal instrument MIDI. The
  aim of this study is to provide observational constraints on
  theoretical prediction that the winds of M-type AGB objects can be
  driven by photon scattering on iron-free silicate grains located in
  the close environment (about 2 to 3 stellar radii) of the star. <BR
  /> Methods: We interpreted spectro-interferometric data, first using
  wavelength-dependent geometric models. We then used a self-consistent
  dynamic model atmosphere containing a time-dependent description
  of grain growth for pure forsterite dust particles to reproduce
  the photometric, spectrometric, and interferometric measurements of
  <ASTROBJ>RT Vir</ASTROBJ>. Since the hydrodynamic computation needs
  stellar parameters as input, a considerable effort was first made to
  determine these parameters. <BR /> Results: MIDI differential phases
  reveal the presence of an asymmetry in the stellar vicinity. Results
  from the geometrical modeling give us clues to the presence of aluminum
  and silicate dust in the close circumstellar environment (&lt;5
  stellar radii). Comparison between spectro-interferometric data and a
  self-consistent dust-driven wind model reveals that silicate dust has
  to be present in the region between 2 to 3 stellar radii to reproduce
  the 59 and 63 m baseline visibility measurements around 9.8 μm. This
  gives additional observational evidence in favor of winds driven by
  photon scattering on iron-free silicate grains located in the close
  vicinity of an M-type star. However, other sources of opacity are
  clearly missing to reproduce the 10-13 μm visibility measurements
  for all baselines. <BR /> Conclusions: This study is a first attempt
  to understand the wind mechanism of M-type AGB stars by comparing
  photometric, spectrometric, and interferometric measurements with
  state-of-the-art, self-consistent dust-driven wind models. The agreement
  of the dynamic model atmosphere with interferometric measurements in
  the 8-10 μm spectral region gives additional observational evidence
  that the winds of M-type stars can be driven by photon scattering on
  iron-free silicate grains. Finally, a larger statistical study and
  progress in advanced self-consistent 3D modeling are still required
  to solve the remaining problems. <P />Based on observations made with
  the Very Large Telescope Interferometer at Paranal Observatory under
  programs 083.D-0234 and 086.D-0737 (Open Time Observations).

---------------------------------------------------------
Title: Comparative modelling of the spectra of cool giants⋆⋆⋆
Authors: Lebzelter, T.; Heiter, U.; Abia, C.; Eriksson, K.; Ireland,
   M.; Neilson, H.; Nowotny, W.; Maldonado, J.; Merle, T.; Peterson,
   R.; Plez, B.; Short, C. I.; Wahlgren, G. M.; Worley, C.; Aringer,
   B.; Bladh, S.; de Laverny, P.; Goswami, A.; Mora, A.; Norris, R. P.;
   Recio-Blanco, A.; Scholz, M.; Thévenin, F.; Tsuji, T.; Kordopatis,
   G.; Montesinos, B.; Wing, R. F.
2012A&A...547A.108L    Altcode: 2012arXiv1209.2656L
  Context. Our ability to extract information from the spectra of stars
  depends on reliable models of stellar atmospheres and appropriate
  techniques for spectral synthesis. Various model codes and strategies
  for the analysis of stellar spectra are available today. <BR /> Aims:
  We aim to compare the results of deriving stellar parameters using
  different atmosphere models and different analysis strategies. The
  focus is set on high-resolution spectroscopy of cool giant stars. <BR
  /> Methods: Spectra representing four cool giant stars were made
  available to various groups and individuals working in the area
  of spectral synthesis, asking them to derive stellar parameters
  from the data provided. The results were discussed at a workshop
  in Vienna in 2010. Most of the major codes currently used in the
  astronomical community for analyses of stellar spectra were included
  in this experiment. <BR /> Results: We present the results from
  the different groups, as well as an additional experiment comparing
  the synthetic spectra produced by various codes for a given set of
  stellar parameters. Similarities and differences of the results are
  discussed. <BR /> Conclusions: Several valid approaches to analyze a
  given spectrum of a star result in quite a wide range of solutions. The
  main causes for the differences in parameters derived by different
  groups seem to lie in the physical input data and in the details of the
  analysis method. This clearly shows how far from a definitive abundance
  analysis we still are. <P />Based on observations obtained at the
  Bernard Lyot Telescope (TBL, Pic du Midi, France) of the Midi-Pyrénées
  Observatory, which is operated by the Institut National des Sciences
  de l'Univers of the Centre National de la Recherche Scientifique
  of France.Tables 6-11 are only available in electronic form at <A
  href="http://www.aanda.org">http://www.aanda.org</A>The spectra of stars
  1 to 4 used in the experiment presented here are only availalbe at the
  CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A108">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A108</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: Comparative modelling of cool
    giants spectra (Lebzelter+, 2012)
Authors: Lebzelter, T.; Heiter, U.; Abia, C.; Eriksson, K.; Ireland,
   M.; Neilson, H.; Nowotny, W.; Maldonado, J.; Merle, T.; Peterson,
   R.; Plez, B.; Short, C. I.; Wahlgren, G. M.; Worley, C.; Aringer,
   B.; Bladh, S.; de Laverny, P.; Goswami, A.; Mora, A.; Norris, R. P.;
   Recio-Blanco, A.; Scholz, M.; Thevenin, F.; Tsuji, T.; Kordopatis,
   G.; Montesinos, B.; Wing, R. F.
2012yCat..35470108L    Altcode: 2012yCat..35479108L
  Spectra representing four cool giant stars were made available
  to various groups and individuals working in the area of spectral
  synthesis, asking them to derive stellar parameters from the data
  provided. The results were discussed at a workshop in Vienna in
  2010. Most of the major codes currently used in the astronomical
  community for analyses of stellar spectra were included in this
  experiment. <P />The files contain the spectra in the same form as
  they were made available to the experiment participants. <P />The
  spectra for Star 1 and Star 2 are on the heliocentric wavelength
  scale (i.e. corrected for Earth motion, but not for stellar radial
  velocity). The spectra are normalized to the continuum by an
  automatic pipeline, which first divides the spectrum by a flat
  field response function and then removes the overall slope of
  the whole spectrum. These optical spectra also contain a number
  of telluric lines. <P />The spectra for Star 3 and Star 4 are on
  the laboratory wavelength scale and the flux is normalized to the
  continuum. They do not contain telluric lines. <P />Additional
  information which was provided to the experiment participants:
  ----------------------------------------------------------------
  FileName Spectral resolution Signal-to-noise ratio
  ----------------------------------------------------------------
  star1.dat 80000 463 at 871 nm star2.dat 80000 517
  at 871 nm star3.dat 70000 125 star4.dat 70000 125
  ----------------------------------------------------------------
  <P />(10 data files).

---------------------------------------------------------
Title: The Oxygen Abundance of the Ultra-metal-poor Star HE 0557-4840
Authors: Norris, John E.; Christlieb, N.; Bessell, M. S.; Asplund,
   M.; Eriksson, K.; Korn, A. J.
2012ApJ...753..150N    Altcode:
  We present a high-resolution ultraviolet (UV) spectrum of the
  ultra-metal-poor (UMP) carbon-enhanced red giant HE 0557-4840 (T
  <SUB> eff</SUB>/log g/[Fe/H] = 4900/2.2/-4.8). Combining these data
  with earlier observations, the radial velocity is 212.0 ± 0.4 km
  s<SUP>-1</SUP>, with no evidence of variability during 2006 February
  to 2007 December. One-dimensional (1D) LTE model-atmosphere analysis
  of UV Fe and CH lines confirms the iron and carbon abundances obtained
  previously ([Fe/H] = -4.8 and [C/Fe]<SUB>1D</SUB> = +1.7), and places
  a more stringent limit on nitrogen abundance of [N/Fe]<SUB>1D</SUB>
  &lt; +1.0. Analysis of the UV OH lines yields [O/Fe]<SUB>1D</SUB>
  = +2.3 ± 0.4. When corrections are made for three-dimensional (3D)
  effects we obtain [C/Fe]<SUB>3D</SUB> = +1.1, [N/Fe]<SUB>3D</SUB> &lt;
  +0.1, and [O/Fe]<SUB>3D</SUB> = +1.4. Comparison of the abundances
  of HE 0557-4840 with those of supernova models of Nomoto et al. and
  Joggerst et al. suggests that none is able to explain fully the observed
  abundance pattern. For HE 0557-4840, the Frebel et al. transition
  discriminant D <SUB>trans</SUB>(= log(10<SUP>[C/H]</SUP> + 0.3 ×
  10<SUP>[O/H]</SUP>) = -3.4 ± 0.2, consistent with fine-structure
  transitions of C II and O I being a major cooling mechanism of
  star-forming regions at the earliest times. Of the four stars known
  to have [Fe/H] &lt;~ -4.3, three are strongly carbon and oxygen
  enhanced. If the suggestion by Caffau et al. that SDSS J102915+172927
  ([Fe/H] = -4.7) does not belong to the class of C-rich, O-rich, UMP
  stars is supported by future similar discoveries, one will need to
  consider multiple channels for the production of stars having [Fe/H]
  &lt;~ -4.3. <P />Based on observations collected at European Southern
  Observatory, Paranal, Chile (proposal 380.D-0040).

---------------------------------------------------------
Title: Determination of rotation periods in solar-like stars with
irregular sampling: the Gaia case
Authors: Distefano, E.; Lanzafame, A. C.; Lanza, A. F.; Messina, S.;
   Korn, A. J.; Eriksson, K.; Cuypers, J.
2012MNRAS.421.2774D    Altcode: 2012arXiv1202.0759D; 2012MNRAS.tmp.2452D
  We present a study on the determination of rotation periods (P) of
  solar-like stars from the photometric irregular time sampling of the
  European Space Agency Gaia mission, currently scheduled for launch in
  2013, taking into account its dependence on ecliptic coordinates. We
  examine the case of solar twins as well as thousands of synthetic time
  series of solar-like stars rotating faster than the Sun. In the case of
  solar twins, we assume that the Gaia unfiltered photometric passband G
  will mimic the variability of the total solar irradiance as measured by
  the Variability of solar IRradiance and Gravity Oscillations (VIRGO)
  experiment. For stars rotating faster than the Sun, light curves are
  simulated using synthetic spectra for the quiet atmosphere, the spots
  and the faculae combined by applying semi-empirical relationships
  relating the level of photospheric magnetic activity to the stellar
  rotation and the Gaia instrumental response. The capabilities of the
  Deeming, Lomb-Scargle and phase dispersion minimization methods in
  recovering the correct rotation periods are tested and compared. The
  false alarm probability is computed using Monte Carlo simulations
  and compared with analytical formulae. The Gaia scanning law makes
  the rate of correct detection of rotation periods strongly dependent
  on the ecliptic latitude (β). We find that for P≃ 1 d, the rate of
  correct detection increases with β from 20-30 per cent at β≃ 0 to
  a peak of 70 per cent at β= 45°; then it abruptly falls below 10 per
  cent at β &gt; 45°. For P &gt; 5 d, the rate of correct detection
  is quite low and for solar twins is only 5 per cent on average.

---------------------------------------------------------
Title: The Gaia-ESO Public Spectroscopic Survey
Authors: Gilmore, G.; Randich, S.; Asplund, M.; Binney, J.; Bonifacio,
   P.; Drew, J.; Feltzing, S.; Ferguson, A.; Jeffries, R.; Micela, G.;
   Negueruela, I.; Prusti, T.; Rix, H. -W.; Vallenari, A.; Alfaro, E.;
   Allende-Prieto, C.; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia,
   A.; Flaccomio, E.; François, P.; Irwin, M.; Koposov, S.; Korn, A.;
   Lanzafame, A.; Pancino, E.; Paunzen, E.; Recio-Blanco, A.; Sacco,
   G.; Smiljanic, R.; Van Eck, S.; Walton, N.; Aden, D.; Aerts, C.;
   Affer, L.; Alcala, J. -M.; Altavilla, G.; Alves, J.; Antoja, T.;
   Arenou, F.; Argiroffi, C.; Asensio Ramos, A.; Bailer-Jones, C.;
   Balaguer-Nunez, L.; Bayo, A.; Barbuy, B.; Barisevicius, G.; Barrado
   y Navascues, D.; Battistini, C.; Bellas Velidis, I.; Bellazzini, M.;
   Belokurov, V.; Bergemann, M.; Bertelli, G.; Biazzo, K.; Bienayme, O.;
   Bland-Hawthorn, J.; Boeche, C.; Bonito, S.; Boudreault, S.; Bouvier,
   J.; Brandao, I.; Brown, A.; de Bruijne, J.; Burleigh, M.; Caballero,
   J.; Caffau, E.; Calura, F.; Capuzzo-Dolcetta, R.; Caramazza, M.;
   Carraro, G.; Casagrande, L.; Casewell, S.; Chapman, S.; Chiappini,
   C.; Chorniy, Y.; Christlieb, N.; Cignoni, M.; Cocozza, G.; Colless,
   M.; Collet, R.; Collins, M.; Correnti, M.; Covino, E.; Crnojevic,
   D.; Cropper, M.; Cunha, M.; Damiani, F.; David, M.; Delgado, A.;
   Duffau, S.; Edvardsson, B.; Eldridge, J.; Enke, H.; Eriksson, K.;
   Evans, N. W.; Eyer, L.; Famaey, B.; Fellhauer, M.; Ferreras, I.;
   Figueras, F.; Fiorentino, G.; Flynn, C.; Folha, D.; Franciosini,
   E.; Frasca, A.; Freeman, K.; Fremat, Y.; Friel, E.; Gaensicke, B.;
   Gameiro, J.; Garzon, F.; Geier, S.; Geisler, D.; Gerhard, O.; Gibson,
   B.; Gomboc, A.; Gomez, A.; Gonzalez-Fernandez, C.; Gonzalez Hernandez,
   J.; Gosset, E.; Grebel, E.; Greimel, R.; Groenewegen, M.; Grundahl,
   F.; Guarcello, M.; Gustafsson, B.; Hadrava, P.; Hatzidimitriou, D.;
   Hambly, N.; Hammersley, P.; Hansen, C.; Haywood, M.; Heber, U.; Heiter,
   U.; Held, E.; Helmi, A.; Hensler, G.; Herrero, A.; Hill, V.; Hodgkin,
   S.; Huelamo, N.; Huxor, A.; Ibata, R.; Jackson, R.; de Jong, R.;
   Jonker, P.; Jordan, S.; Jordi, C.; Jorissen, A.; Katz, D.; Kawata,
   D.; Keller, S.; Kharchenko, N.; Klement, R.; Klutsch, A.; Knude,
   J.; Koch, A.; Kochukhov, O.; Kontizas, M.; Koubsky, P.; Lallement,
   R.; de Laverny, P.; van Leeuwen, F.; Lemasle, B.; Lewis, G.; Lind,
   K.; Lindstrom, H. P. E.; Lobel, A.; Lopez Santiago, J.; Lucas, P.;
   Ludwig, H.; Lueftinger, T.; Magrini, L.; Maiz Apellaniz, J.; Maldonado,
   J.; Marconi, G.; Marino, A.; Martayan, C.; Martinez-Valpuesta, I.;
   Matijevic, G.; McMahon, R.; Messina, S.; Meyer, M.; Miglio, A.;
   Mikolaitis, S.; Minchev, I.; Minniti, D.; Moitinho, A.; Momany, Y.;
   Monaco, L.; Montalto, M.; Monteiro, M. J.; Monier, R.; Montes, D.;
   Mora, A.; Moraux, E.; Morel, T.; Mowlavi, N.; Mucciarelli, A.; Munari,
   U.; Napiwotzki, R.; Nardetto, N.; Naylor, T.; Naze, Y.; Nelemans, G.;
   Okamoto, S.; Ortolani, S.; Pace, G.; Palla, F.; Palous, J.; Parker, R.;
   Penarrubia, J.; Pillitteri, I.; Piotto, G.; Posbic, H.; Prisinzano,
   L.; Puzeras, E.; Quirrenbach, A.; Ragaini, S.; Read, J.; Read, M.;
   Reyle, C.; De Ridder, J.; Robichon, N.; Robin, A.; Roeser, S.; Romano,
   D.; Royer, F.; Ruchti, G.; Ruzicka, A.; Ryan, S.; Ryde, N.; Santos,
   N.; Sanz Forcada, J.; Sarro Baro, L. M.; Sbordone, L.; Schilbach, E.;
   Schmeja, S.; Schnurr, O.; Schoenrich, R.; Scholz, R. -D.; Seabroke, G.;
   Sharma, S.; De Silva, G.; Smith, M.; Solano, E.; Sordo, R.; Soubiran,
   C.; Sousa, S.; Spagna, A.; Steffen, M.; Steinmetz, M.; Stelzer, B.;
   Stempels, E.; Tabernero, H.; Tautvaisiene, G.; Thevenin, F.; Torra,
   J.; Tosi, M.; Tolstoy, E.; Turon, C.; Walker, M.; Wambsganss, J.;
   Worley, C.; Venn, K.; Vink, J.; Wyse, R.; Zaggia, S.; Zeilinger, W.;
   Zoccali, M.; Zorec, J.; Zucker, D.; Zwitter, T.; Gaia-ESO Survey Team
2012Msngr.147...25G    Altcode:
  The Gaia-ESO Public Spectroscopic Survey has begun and will obtain high
  quality spectroscopy of some 100000 Milky Way stars, in the field and
  in open clusters, down to magnitude 19, systematically covering all the
  major components of the Milky Way. This survey will provide the first
  homogeneous overview of the distributions of kinematics and chemical
  element abundances in the Galaxy. The motivation, organisation and
  implementation of the Gaia-ESO Survey are described, emphasising the
  complementarity with the ESA Gaia mission. Spectra from the very first
  observing run of the survey are presented.

---------------------------------------------------------
Title: Synthetic Spectra and Photometry of C-rich Hydrodynamical
    Model Atmospheres
Authors: Wachter, A.; Eriksson, K.; Aringer, B.; Höfner, S.;
   Nowotny, W.
2011ASPC..448..969W    Altcode: 2011csss...16..969W
  We have calculated synthetic spectra for a set of hydrodynamical
  dust-driven wind models with carbon-rich chemistry to investigate their
  optical and infrared appearance depending on model parameters. The
  spectra were computed at various phases covering several pulsation
  periods to examine cycle-to-cycle variations. Furthermore, we determined
  photometric magnitudes in different broadband filters to present and
  compare lightcurves. Relations between mass-loss rates and colour
  indices are also dicussed.

---------------------------------------------------------
Title: A grid of S stars MARCS model atmospheres
Authors: Van Eck, Sophie; Neyskens, Pieter; Plez, Bertrand; Jorissen,
   Alain; Edvardsson, Bengt; Eriksson, Kjell; Gustafsson, Bengt; Gråe
   Jørgensen, Uffe; Nordlund, Åke
2011JPhCS.328a2009V    Altcode:
  S stars are cool stars of temperatures similar to those of M giants,
  but their atmospheres are enriched in carbon and s-process elements
  because of either extrinsic pollution by a binary companion or intrinsic
  nucleosynthesis and dredge-up on the thermally-pulsing AGB. Despite
  numerous attempts to link phenomenological spectral classification
  criteria to physical parameters (T<SUB>eff</SUB>, gravity, C/O, [s/Fe],
  [Fe/H]), the parameter space of S stars is poorly known and this has
  prevented accurate abundance analysis of S stars until now. Here we
  present a large grid of S-star model atmospheres. ZrO and TiO band
  strength indices as well as VJHKL photometry are needed to disentangle
  the effective temperature, C/O and [s/Fe]. The stellar parameters
  derived on the basis of low-resolution spectra and photometry are
  shown to be fairly accurate when compared to high-resolution data
  of the same stars. The C/O ratio of S stars is found to be between
  the solar value (0.5) and 0.99, and not 1 as often claimed in the
  literature. Consistently with stellar evolution expectations, the C/O
  ratio increases as the effective temperature decreases.

---------------------------------------------------------
Title: Analysis of old very metal rich stars in the solar
    neighbourhood
Authors: Trevisan, M.; Barbuy, B.; Eriksson, K.; Gustafsson, B.;
   Grenon, M.; Pompéia, L.
2011A&A...535A..42T    Altcode: 2011arXiv1109.6304T
  Context. A sample of mostly old metal-rich dwarf and turn-off stars with
  high eccentricity and low maximum height above the Galactic plane has
  been identified. From their kinematics, it was suggested that the inner
  disk is their most probable birthplace. Their chemical imprints may
  therefore reveal important information about the formation and evolution
  of the still poorly understood inner disk. <BR /> Aims: To probe the
  formation history of these stellar populations, a detailed analysis
  of a sample of very metal-rich stars is carried out. We derive the
  metallicities, abundances of α elements, ages, and Galactic orbits. <BR
  /> Methods: The analysis of 71 metal-rich stars is based on optical
  high-resolution échelle spectra obtained with the FEROS spectrograph
  at the ESO 1.52-m Telescope at La Silla, Chile. The metallicities
  and abundances of C, O, Mg, Si, Ca, and Ti were derived based on LTE
  detailed analysis, employing the MARCS model atmospheres. <BR />
  Results: We confirm the high metallicity of these stars reaching
  up to [Fe i/H] = 0.58, and the sample of metal-rich dwarfs can be
  kinematically subclassified in samples of thick disk, thin disk, and
  intermediate stellar populations. All sample stars show solar α-Fe
  ratios, and most of them are old and still quite metal rich. The orbits
  suggest that the thin disk, thick disk and intermediate populations
  were formed at Galactocentric distances of ~8 kpc, ~6 kpc, and ~7 kpc,
  respectively. The mean maximum height of the thick disk subsample of
  Z<SUB>max</SUB> ~ 380 pc, is lower than for typical thick disk stars. A
  comparison of α-element abundances of the sample stars with bulge stars
  shows that the oxygen is compatible with a bulge or inner thick disk
  origin. Our results suggest that models of radial mixing and dynamical
  effects of the bar and bar/spiral arms might explain the presence
  of these old metal-rich dwarf stars in the solar neighbourhood. <P
  />Observations collected at the European Southern Observatory, La
  Silla, Chile.Full Tables A.1 to A.4 are only available at the CDS
  via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via <A
  href="http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A42">http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/535/A42</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: Metal rich stars in solar
    neighbourhood (Trevisan+, 2011)
Authors: Trevisan, M.; Barbuy, B.; Eriksson, K.; Gustafsson, B.;
   Grenon, M.; Pompeia, L.
2011yCat..35350042T    Altcode: 2011yCat..35359042T
  Spectroscopic stellar parameters and abundances of C, O, Mg, Si, Ca, Ti
  and Ni for 71 stars. U, V, W velocities and orbital parameters derived
  using the GRINTON integrator (Carraro et al. 2002MNRAS.332..705C,
  Bedin et al. 2006A&amp;A...460L..27B). Atomic data for Fe I, Fe II,
  Si I, Ca I, and Ti I lines. <P />(7 data files).

---------------------------------------------------------
Title: Structure of the outer layers of cool standard stars
Authors: Dehaes, S.; Bauwens, E.; Decin, L.; Eriksson, K.; Raskin,
   G.; Butler, B.; Dowell, C. D.; Ali, B.; Blommaert, J. A. D. L.
2011A&A...533A.107D    Altcode: 2009arXiv0905.1240D
  Context. Among late-type red giants, an interesting change occurs in
  the structure of the outer atmospheric layers as one moves to later
  spectral types in the Hertzsprung-Russell diagram: a chromosphere
  is always present, but the coronal emission diminishes and a cool
  massive wind steps in. <BR /> Aims: Where most studies have focussed
  on short-wavelength observations, this article explores the influence
  of the chromosphere and the wind on long-wavelength photometric
  measurements. The goal of this study is to assess wether a set of
  standard near-infrared calibration sources are fiducial calibrators
  in the far-infrared, beyond 50 μm. <BR /> Methods: The observational
  spectral energy distributions were compared with the theoretical model
  predictions for a sample of nine K- and M-giants. The discrepancies
  found are explained using basic models for flux emission originating
  in a chromosphere or an ionised wind. <BR /> Results: For seven out of
  nine sample stars, a clear flux excess is detected at (sub)millimetre
  and/or centimetre wavelengths, while only observational upper limits
  are obtained for the other two. The precise start of the excess depends
  upon the star under consideration. For six sources the flux excess
  starts beyond 210 μm and they can be considered as fiducial calibrators
  for Herschel/PACS (60-210 μm). Out of this sample, four sources show
  no flux excess in the Herschel/SPIRE wavelength range (200-670 μm)
  and are good calibration sources for this instrument as well. The
  flux at wavelengths shorter than ~1 mm is most likely dominated by an
  optically thick chromosphere, where an optically thick ionised wind is
  the main flux contributor at longer wavelengths. <BR /> Conclusions:
  Although the optical to mid-infrared spectrum of the studied K- and
  M-type infrared standard stars is represented well by a radiative
  equilibrium atmospheric model, a chromosphere and/or ionised stellar
  wind at higher altitudes dominates the spectrum in the (sub)millimetre
  and centimetre wavelength ranges. The presence of a flux excess has
  implications on the role of the stars as fiducial spectrophotometric
  calibrators in these wavelength ranges. <P />Appendix A is available in
  electronic form at <A href="http:www.aanda.org">http:www.aanda.org</A>

---------------------------------------------------------
Title: VizieR Online Data Catalog: SED for 7 stellar calibrators
    (Dehaes+, 2011)
Authors: Dehaes, S.; Bauwens, E.; Decin, L.; Eriksson, K.; Raskin,
   G.; Butler, B.; Dowell, C. D.; Ali, B.; Blommaert, J. A. D. L.
2011yCat..35330107D    Altcode: 2011yCat..35339107D
  This catalogue presents the theoretical spectral energy distributions
  for 7 stellar calibrators of the ESA Herschel satellite in the
  wavelength range from 2 to 200 micron. <P />The stellar atmosphere model
  and theoretical spectrum are generated using the MARCS theoretical
  stellar atmosphere code (Gustafsson et al., 1975A&amp;A....42..407G
  and further updates; Gustafsson et al. 2003A&amp;A...400..709D)
  and the TURBOSPECTRUM synthetic spectrum code (Plez et al.,
  1992A&amp;A...256..551P). Stellar parameters (and uncertainties thereon)
  have been derived by Decin et al. (2003A&amp;A...400..709D) and are
  described in the text files added to this catalogue. The line lists used
  in the spectrum calculation are discussed in Decin (2000, PhD Thesis,
  Leuven University) and Decin and Eriksson (2007A&amp;A...472.1041D). <P
  />The outermost depth point of the theoretical atmosphere model
  was taken at log(tau<SUB>lambda</SUB>)=-7.2 with lambda being 2.2
  micron. The atmosphere model was calculated with a spherically
  symmetric (parallel for Sirius) geometry, under the assumption of
  radiative and hydrostatic equilibrium, local thermodynamic equilibrium
  (LTE) and homogeneous layers. <P />The original theoretical spectrum
  was calculated at a resolution of Δλ=0.5Å, and then degraded to
  a resolution of λ/Δλ=5000 applying a gaussian convolution. The
  wavelength coverage is from 2 to 200 micron. <P />Uncertainties on the
  theoretical spectrum predictions are discussed in depth in Decin &amp;
  Eriksson (2007A&amp;A...472.1041D). <P />Absolute flux calibration
  is based on Selby (1988A&amp;AS...74..127S) K-band (TCS for Sirius)
  photometry <P />Zero-point is determined on the basis of an ideal
  'Vega', i.e. the K-band photometry of Vega is corrected for a flux
  excess of 1.29% (cf. Absil et al. 2006A&amp;A...452..237A). The
  determined Selby K-band zeropoint is 4.0517E-10 W/m2/um. The
  determined TCS K-band zeropoint is 4.4506E-10W/m2/um (for Sirius)
  <P />The estimated absolute flux uncertainty is 1% <P />These
  theoretical spectra should be referenced as Decin &amp; Eriksson
  (2007A&amp;A...472.1041D). <P />(3 data files).

---------------------------------------------------------
Title: A Grid of MARCS Model Atmospheres for S Stars
Authors: van Eck, S.; Neyskens, P.; Plez, B.; Jorissen, A.; Edvardsson,
   B.; Eriksson, K.; Gustafsson, B.; Jørgensen, U. G.; Nordlund, Å.
2011ASPC..445...71V    Altcode: 2010arXiv1011.2092V
  S-type stars are late-type giants whose atmospheres are enriched in
  carbon and s-process elements because of either extrinsic pollution by
  a binary companion or intrinsic nucleosynthesis and dredge-up on the
  thermally-pulsing AGB. A large grid of S-star model atmospheres has
  been computed covering the range 2700 ≤ T<SUB>eff</SUB>(K) ≤ 4000
  with 0.5 ≤ C/O ≤ 0.99. ZrO and TiO band strength indices as well
  as VJHKL photometry are needed to disentangle T<SUB>eff</SUB>, C/O and
  [s/Fe]. A “best-model finding tool” has been developed using a set
  of well-chosen indices and checked against photometry as well as low-
  and high-resolution spectroscopy. It is found that applying M-star
  model atmospheres (i.e., with a solar C/O ratio) to S stars can lead
  to errors in T<SUB>eff</SUB> up to 400 K. We constrain the parameter
  space occupied by the S stars of the vast Henize sample in terms of
  T<SUB>eff</SUB>, [C/O] and [s/Fe].

---------------------------------------------------------
Title: Synthetic Colors for Dynamic C-Star Models
Authors: Eriksson, K.; Wachter, A.; Höfner, S.; Aringer, B.;
   Nowotny, W.
2011ASPC..445..325E    Altcode:
  Dust is formed in the outer atmospheres and winds of AGB stars and
  severely affects their observed spectra and colours. Synthetic JHK
  colours from a grid of time-dependent C-star models are presented
  and compared to observed colours. The combined effects of pulsation
  and dust are significant, especially for the coolest and most luminous
  models. We are now extending the calculations with respect to effective
  temperature, luminosity, stellar mass, and pulsation amplitude, as
  well as the carbon excess.

---------------------------------------------------------
Title: Detached Shells of Dust and Gas around Carbon Stars
Authors: Maercker, M.; Olofsson, H.; Eriksson, K.; Gustafsson, B.;
   Schöier, F. L.
2011ASPC..445..345M    Altcode:
  We present observations of dust-scattered light of the carbon stars
  U Ant, R Scl, and U Cam taken with the EFOSC2 camera on the ESO 3.6-m
  telescope and the ACS on the Hubble Space Telescope. The observations
  show the detached shells around these stars in unprecedented detail,
  revealing a distinctively clumpy structure in the HST images of R Scl,
  and a separation of the dust and gas in the ground-based data for
  U Ant. This allows us to investigate the detached shells and their
  origin with exceptional precision.

---------------------------------------------------------
Title: Sulphur abundances in halo giants from the [S I] line at 1082
    nm and the [S I] triplet around 1045 nm
Authors: Jönsson, H.; Ryde, N.; Nissen, P. E.; Collet, R.; Eriksson,
   K.; Asplund, M.; Gustafsson, B.
2011A&A...530A.144J    Altcode: 2011arXiv1104.2148J
  Context. It is still debated whether or not the Galactic chemical
  evolution of sulphur in the halo follows the flat trend with [Fe/H]
  that is ascribed to the result of explosive nucleosynthesis in type
  II SNe. It has been suggested that the disagreement between different
  investigations of sulphur abundances in halo stars might be owing
  to problems with the diagnostics used, that a new production source
  of sulphur might be needed in the early Universe, like hypernovae, or
  that the deposition of supernova ejecta into the interstellar medium is
  time-delayed. <BR /> Aims: The aim of this study is to try to clarify
  this situation by measuring the sulphur abundance in a sample of halo
  giants using two diagnostics: the S i triplet around 1045 nm and the
  [S i] line at 1082 nm. The latter of the two is not believed to be
  sensitive to non-LTE effects. We can thereby minimize the uncertainties
  in the diagnostic used and estimate the usefulness of the triplet for
  the sulphur determination in halo K giants. We will also be able to
  compare our sulphur abundance differences from the two diagnostics
  with the expected non-LTE effects in the 1045 nm triplet previously
  calculated by others. <BR /> Methods: High-resolution near-infrared
  spectra of ten K giants were recorded using the spectrometer CRIRES
  mounted at VLT. Two standard settings were used, one covering the S i
  triplet and one covering the [S i] line. The sulphur abundances were
  individually determined with equivalent widths and synthetic spectra
  for the two diagnostics using tailored 1D model atmospheres and relying
  on non-LTE corrections from the litterature. Effects of convective
  inhomogeneities in the stellar atmospheres are investigated. <BR />
  Results: The sulphur abundances derived from both the [S i] line and the
  non-LTE corrected 1045 nm triplet favor a flat trend for the evolution
  of sulphur. In contrast to some previous studies, we saw no "high"
  values of [S/Fe] in our sample. <BR /> Conclusions: We corroborate
  the flat trend in the [S/Fe] vs. [Fe/H] plot for halo stars found in
  some previous studies but do not find a scatter or a rise in [S/Fe]
  as obtained in other works. We find the sulphur abundances deduced
  from the non-LTE corrected triplet to be somewhat lower than the
  abundances from the [S i] line, possibly indicating too large non-LTE
  corrections. Considering 3D modeling, however, they might instead
  be too small. Moreover, we show that the [S i] line can be used as
  a sulphur diagnostic down to [Fe/H] ~ -2.3 in giants. <P />Based on
  observations collected at the European Southern Observatory, Chile
  (ESO program 080.D-0675(A)).

---------------------------------------------------------
Title: Ices in the Quiescent IC 5146 Dense Cloud
Authors: Chiar, J. E.; Pendleton, Y. J.; Allamandola, L. J.; Boogert,
   A. C. A.; Ennico, K.; Greene, T. P.; Geballe, T. R.; Keane, J. V.;
   Lada, C. J.; Mason, R. E.; Roellig, T. L.; Sandford, S. A.; Tielens,
   A. G. G. M.; Werner, M. W.; Whittet, D. C. B.; Decin, L.; Eriksson, K.
2011ApJ...731....9C    Altcode: 2011arXiv1102.2488C
  This paper presents spectra in the 2 to 20 μm range of quiescent
  cloud material located in the IC 5146 cloud complex. The spectra were
  obtained with NASA's Infrared Telescope Facility SpeX instrument and
  the Spitzer Space Telescope's Infrared Spectrometer. We use these
  spectra to investigate dust and ice absorption features in pristine
  regions of the cloud that are unaltered by embedded stars. We find that
  the H<SUB>2</SUB>O-ice threshold extinction is 4.03 ± 0.05 mag. Once
  foreground extinction is taken into account, however, the threshold
  drops to 3.2 mag, equivalent to that found for the Taurus dark cloud,
  generally assumed to be the touchstone quiescent cloud against which
  all other dense cloud and embedded young stellar object observations
  are compared. Substructure in the trough of the silicate band for
  two sources is attributed to CH<SUB>3</SUB>OH and NH<SUB>3</SUB> in
  the ices, present at the ~2% and ~5% levels, respectively, relative
  to H<SUB>2</SUB>O-ice. The correlation of the silicate feature with
  the E(J - K) color excess is found to follow a much shallower slope
  relative to lines of sight that probe diffuse clouds, supporting the
  previous results by Chiar et al.

---------------------------------------------------------
Title: An abundance study of red-giant-branch stars in the Hercules
    dwarf spheroidal galaxy
Authors: Adén, D.; Eriksson, K.; Feltzing, S.; Grebel, E. K.; Koch,
   A.; Wilkinson, M. I.
2011A&A...525A.153A    Altcode: 2010arXiv1010.5683A
  Context. Dwarf spheroidal galaxies are some of the most metal-poor,
  and least luminous objects known. Detailed elemental abundance analysis
  of stars in these faint objects is key to our understanding of star
  formation and chemical enrichment in the early universe, and may provide
  useful information on how larger galaxies form. <BR /> Aims: Our aim is
  to provide a determination of [Fe/H] and [Ca/H] for confirmed red-giant
  branch member stars of the Hercules dwarf spheroidal galaxy. Based
  on this we explore the ages of the prevailing stellar populations in
  Hercules, and the enrichment history from supernovae. Additionally,
  we aim to provide a new simple metallicity calibration for Strömgren
  photometry for metal-poor, red giant branch stars. <BR /> Methods:
  High-resolution, multi-fibre spectroscopy and Strömgren photometry are
  combined to provide as much information on the stars as possible. From
  this we derive abundances by solving the radiative transfer equations
  through marcs model atmospheres. <BR /> Results: We find that the
  red-giant branch stars of the Hercules dSph galaxy are more metal-poor
  than estimated in our previous study that was based on photometry
  alone. From this, we derive a new metallicity calibration for the
  Strömgren photometry. Additionally, we find an abundance trend such
  that [Ca/Fe] is higher for more metal-poor stars, and lower for more
  metal-rich stars, with a spread of about 0.8 dex. The [Ca/Fe] trend
  suggests an early rapid chemical enrichment through supernovae of type
  II, followed by a phase of slow star formation dominated by enrichment
  through supernovae of type Ia. A comparison with isochrones indicates
  that the red giants in Hercules are older than 10 Gyr.

---------------------------------------------------------
Title: Fluorine Abundances in Galactic Asymptotic Giant Branch Stars
Authors: Abia, C.; Cunha, K.; Cristallo, S.; de Laverny, P.;
   Domínguez, I.; Eriksson, K.; Gialanella, L.; Hinkle, K.; Imbriani,
   G.; Recio-Blanco, A.; Smith, V. V.; Straniero, O.; Wahlin, R.
2010ApJ...715L..94A    Altcode:
  An analysis of the fluorine abundance in Galactic asymptotic giant
  branch (AGB) carbon stars (24 N-type, 5 SC-type, and 5 J-type) is
  presented. This study uses the state-of-the-art carbon-rich atmosphere
  models and improved atomic and molecular line lists in the 2.3 μm
  region. Significantly lower F abundances are obtained in comparison to
  previous studies in the literature. This difference is mainly due to
  molecular blends. In the case of carbon stars of SC-type, differences
  in the model atmospheres are also relevant. The new F enhancements
  are now in agreement with the most recent theoretical nucleosynthesis
  models in low-mass AGB stars, solving the long-standing problem of F in
  Galactic AGB stars. Nevertheless, some SC-type carbon stars still show
  larger F abundances than predicted by stellar models. The possibility
  that these stars are of larger mass is briefly discussed.

---------------------------------------------------------
Title: High-resolution HST/ACS images of detached shells around
    carbon stars
Authors: Olofsson, H.; Maercker, M.; Eriksson, K.; Gustafsson, B.;
   Schöier, F.
2010A&A...515A..27O    Altcode: 2010arXiv1003.0362O
  Context. Overall spherically symmetric, geometrically thin gas and dust
  shells have been found around a handful of asymptotic giant branch (AGB)
  carbon stars. Their dynamical ages lie in the range of 10<SUP>3</SUP>
  to 10<SUP>4</SUP> years. A tentative explanation for their existence is
  that they have formed as a consequence of mass-loss-rate modulations
  during a He-shell flash. <BR /> Aims: The detached shells carry
  information on their formation process, as well as on the small-scale
  structure of the circumstellar medium around AGB stars due to the
  absence of significant line-of-sight confusion. <BR /> Methods: The
  youngest detached shells, those around the carbon stars R Scl and U
  Cam, are studied here in great detail in scattered stellar light with
  the Advanced Survey Camera on the Hubble Space Telescope. Quantitative
  results are derived assuming optically thin dust scattering. <BR />
  Results: The detached dust shells around R Scl and U Cam are found to
  be consistent with an overall spherical symmetry. They have radii of
  19.2 arcsec (corresponding to a linear size of 8 × 10<SUP>16</SUP>
  cm) and 7.7 arcsec (5 × 10<SUP>16</SUP> cm), widths of 1.2 arcsec
  (5 × 10<SUP>15</SUP> cm) and 0.6 arcsec (4 × 10<SUP>15</SUP> cm),
  and dust masses of 3 × 10<SUP>-6</SUP> and 3 × 10<SUP>-7</SUP> M_⊙,
  respectively. The dynamical ages of the R Scl and U Cam shells are
  estimated to be 1700 and 700 yr, respectively, and the shell widths
  correspond to time scales of 100 and 50 yr, respectively. Small-scale
  structure in the form of less than arcsec-sized clumps is clearly
  seen in the images of the R Scl shell. Average clump dust masses are
  estimated to be about 2 × 10<SUP>-9</SUP> M_⊙. Comparisons with CO
  line interferometer data show that the dust and gas shells coincide
  spatially, within the errors (≤1´´ for U Cam and ≈2´´ for
  R Scl). <BR /> Conclusions: The results are consistent with the
  interpretation of geometrically thin gas and dust shells formed by
  a mass-loss eruption during a He-shell flash, and where interaction
  with a previous wind plays a role as well. The mass loss responsible
  for the shells must have been remarkably isotropic, and, if wind
  interaction plays a role, this also applies to the mass loss prior
  to the eruption. Clumpy structure is present in the R Scl shell,
  possibly as a consequence of the mass loss itself, but more likely
  as a consequence of instabilities in the expanding shell. <P />Based
  on observations with the NASA/ESA Hubble Space Telescope, obtained at
  the Space Telescope Science Insitute, which is operated by the AURA,
  Inc., under NASA contract NAS5-26555.

---------------------------------------------------------
Title: Oxygen Isotopic Ratios in Cool R Coronae Borealis Stars
Authors: García-Hernández, D. A.; Lambert, David L.; Kameswara Rao,
   N.; Hinkle, Ken H.; Eriksson, Kjell
2010ApJ...714..144G    Altcode: 2010arXiv1003.2901A
  We investigate the relationship between R Coronae Borealis (RCB)
  stars and hydrogen-deficient carbon (HdC) stars by measuring precise
  <SUP>16</SUP>O/<SUP>18</SUP>O ratios for five cool RCB stars. The
  <SUP>16</SUP>O/<SUP>18</SUP>O ratios are derived by spectrum synthesis
  from high-resolution (R ~ 50, 000) K-band spectra. Lower limits to the
  <SUP>16</SUP>O/<SUP>17</SUP>O and <SUP>14</SUP>N/<SUP>15</SUP>N ratios
  as well as Na and S abundances (when possible) are also given. RCB
  stars in our sample generally display less <SUP>18</SUP>O than HdC
  stars—the derived <SUP>16</SUP>O/<SUP>18</SUP>O ratios range from 3
  to 20. The only exception is the RCB star WX CrA, which seems to be an
  HdC-like star with <SUP>16</SUP>O/<SUP>18</SUP>O = 0.3. Our result of
  a higher <SUP>16</SUP>O/<SUP>18</SUP>O ratio for the RCB stars must
  be accounted for by a theory of the formation and evolution of HdC
  and RCB stars. We speculate that a late dredge-up of products of He
  burning, principally <SUP>12</SUP>C and <SUP>16</SUP>O, may convert an
  <SUP>18</SUP>O-rich HdC star into an <SUP>18</SUP>O-poor RCB star as
  the H-deficient star begins its final evolution from a cool supergiant
  to the top of the white dwarf cooling track.

---------------------------------------------------------
Title: Lithium abundances in Bulge-like SMR stars
Authors: Barbuy, Beatriz; Trevisan, M.; Gustafsson, B.; Eriksson,
   K.; Grenon, M.; Pompéia, L.
2010IAUS..268..325B    Altcode:
  We analyze a sample of 21 super-metal-rich (SMR) stars, using
  high-resolution échelle spectra obtained with the FEROS Spectrograph
  at the 1.5m ESO telescope. The metallicities are in the range 0.15 &lt;
  [Fe/H] &lt; 0.5, 3 of them in common with Pompéia et al. (2002). Geneva
  photometry, astrometric data from Hipparcos, and radial velocities
  from CORAVEL are available for these stars. The peculiar kinematics
  suggests the thin disk close to the bulge as the probable birthplace
  of these stars (Grenon 1999). From Hipparcos data, it appears that
  the turnoff of this population indicates an age of 10-11 Gyr (Grenon
  1999). Detailed analysis of the sample stars is carried out. Lithium
  abundances of these stars were derived, and their behaviour with
  effective temperature is shown.

---------------------------------------------------------
Title: Fluorine Abundances in Galactic AGB Stars
Authors: Abia, C.; Cunha, K.; Cristallo., S.; de Laverny, P.;
   Dominguez, I.; Eriksson, K.; Gialanella, L.; Hinkle, K.; Imbriani,
   G.; Recio-Blanco, A; Smith, V. V.; Straniero, O.; Wahlin, R.
2010arXiv1004.4451A    Altcode:
  An analysis of the fluorine abundance in Galactic AGB carbon stars
  (24 N-type, 5 SC-type and 5 J-type) is presented. This study uses the
  state- of-the-art carbon rich atmosphere models and improved atomic
  and molecular line lists in the 2.3 {\mu}m region. F abundances
  significantly lower are obtained in comparison to previous study in
  the literature. The main reason of this difference is due to molecular
  blends. In the case of carbon stars of SC-type, differences in the
  model atmospheres are also relevant. The new F enhancements are now in
  agreement with the most recent theoretical nucleosynthesis models in
  low- mass AGB stars, solving the long standing problem of F in Galactic
  AGB stars. Nevertheless, some SC-type carbon stars still show larger
  F abundances than predicted by stellar models. The possibility that
  these stars are of larger mass is briefly discussed.

---------------------------------------------------------
Title: The detached dust and gas shells around the carbon star
    U Antliae
Authors: Maercker, M.; Olofsson, H.; Eriksson, K.; Gustafsson, B.;
   Schöier, F. L.
2010A&A...511A..37M    Altcode: 2009arXiv0912.2673M
  Context. Geometrically thin, detached shells of gas have been found
  around a handful of carbon stars. The current knowledge on these shells
  is mostly based on CO radio line data. However, imaging in scattered
  stellar light adds important new information as well as allows studies
  of the dust shells. <BR /> Aims: Previous observations of scattered
  stellar light in the circumstellar medium around the carbon star U
  Ant were taken through filters centred on the resonance lines of K
  and Na. These observations could not separate the scattering by dust
  and atoms. The aim of this paper is to remedy this situation. <BR />
  Methods: We have obtained polarization data on stellar light scattered
  in the circumstellar medium around U Ant through filters which contain
  no strong lines, making it possible to differentiate between the two
  scattering agents. Kinematic, as well as spatial, information on the
  gas shells were obtained through high-resolution echelle spectrograph
  observations of the KI and NaD lines. <BR /> Results: We confirm the
  existence of two detached shells around U Ant. The inner shell (at a
  radius of ≈43´´ and a width of ≈2´´) consists mainly of gas,
  while the outer shell (at a radius of ≈50´´ and a width of ≈7´´)
  appears to consist exclusively of dust. Both shells appear to have
  an over-all spherical geometry. The gas shell mass is estimated to
  be 2 × 10<SUP>-3</SUP>~M<SUB>⊙</SUB>, while the mass of the dust
  shell is estimated to be 5 × 10<SUP>-5</SUP>~M<SUB>⊙</SUB>. The
  derived expansion velocity, from the KI and NaD lines, of the gas
  shell, 19.5 km s<SUP>-1</SUP>, agrees with that obtained from CO radio
  line data. The inferred shell age is 2700 years. There is structure,
  e.g. in the form of arcs, inside the gas shell, but it is not clear
  whether these are due to additional shells. <BR /> Conclusions: Our
  results support the hypothesis that the observed geometrically thin,
  detached shells around carbon stars are the results of brief periods
  of intense mass loss, probably associated with thermal pulses, and
  subsequent wind-wind interactions. The separation into a gas and a dust
  shell, with different widths, is most likely the effect of different
  dynamical evolutions of the two media after their ejection.

---------------------------------------------------------
Title: Is the fluorine abundance problem in AGB stars solved? .
Authors: Abia, C.; Cunha, K.; Cristallo, S.; de Laverny, P.;
   Domínguez, I.; Eriksson, K.; Gialanella, L.; Hinkle, K.; Imbriani,
   G.; Recio-Blanco, A.; Smith, V. V.; Straniero, O.; Wahlin, R.
2010MmSAI..81..986A    Altcode:
  A reanalysis of the fluorine abundance in Galactic AGB carbon stars
  has been performed from several HF (1-0) molecular lines in the 2.3
  mu m range. High-resolution and high signal to noise spectra from the
  FTS spectrograph were obtained from the NOAO archive. Using spectral
  synthesis in LTE we derive fluorine abundances that are systematically
  lower by ∼ 0.7 dex on average with respect to previous estimates. We
  conclude that the reason for this relies mainly on differences in the
  molecular line list, which has been largely improved in this work. The
  new F abundances are in much better agreement with the predictions
  from full network stellar models of low mass AGB stars.

---------------------------------------------------------
Title: Evidence of enrichment by individual SN from elemental
    abundance ratios in the very metal-poor dSph galaxy Boötes I
Authors: Feltzing, S.; Eriksson, K.; Kleyna, J.; Wilkinson, M. I.
2009A&A...508L...1F    Altcode: 2009arXiv0910.1557F
  Aims. We establish the mean metallicity from high-resolution
  spectroscopy for the recently found dwarf spheroidal galaxy Boötes
  I and test whether it is a common feature for ultra-faint dwarf
  spheroidal galaxies to show signs of inhomogeneous chemical evolution
  (e.g. as found in the Hercules dwarf spheroidal galaxy).<BR /> Methods:
  We analyse high-resolution, moderate signal-to-noise spectra for seven
  red giant stars in the Boötes I dSph galaxy using standard abundance
  analysis techniques. In particular, we assume local thermodynamic
  equilibrium and employ spherical model atmospheres and codes that take
  the sphericity of the star into account when calculating the elemental
  abundances.<BR /> Results: We confirm previous determinations of the
  mean metallicity of the Boötes I dwarf spheroidal galaxy to be -2.3
  dex. Whilst five stars are clustered around this metallicity, one is
  significantly more metal-poor, at -2.9 dex, and one is more metal-rich
  at, -1.9 dex. Additionally, we find that one of the stars, Boo-127,
  shows an atypically high [Mg/Ca] ratio, indicative of stochastic
  enrichment processes within the dSph galaxy. Similar results have
  previously only been found in the Hercules and Draco dSph galaxies and
  appear, so far, to be unique to this type of galaxy.<BR /> <P />The
  data presented herein were obtained at the W.M. Keck Observatory,
  which is operated as a scientific partnership among the California
  Institute of Technology, the University of California and the National
  Aeronautics and Space Administration. The Observatory was made possible
  by the generous financial support of the W.M. Keck Foundation.

---------------------------------------------------------
Title: The Hamburg/ESO R-process enhanced star survey
    (HERES). IV. Detailed abundance analysis and age dating of the
    strongly r-process enhanced stars CS 29491-069 and HE 1219-0312
Authors: Hayek, W.; Wiesendahl, U.; Christlieb, N.; Eriksson, K.;
   Korn, A. J.; Barklem, P. S.; Hill, V.; Beers, T. C.; Farouqi, K.;
   Pfeiffer, B.; Kratz, K. -L.
2009A&A...504..511H    Altcode: 2009arXiv0910.0707H
  We report on a detailed abundance analysis of two strongly
  r-process enhanced, very metal-poor stars newly discovered in
  the HERES project, <ASTROBJ>CS 29491-069</ASTROBJ> ([Fe/H]=-2.51,
  [r/Fe]=+1.1) and <ASTROBJ>HE 1219-0312</ASTROBJ> ([Fe/H]=-2.96,
  [r/Fe]=+1.5). The analysis is based on high-quality VLT/UVES spectra
  and MARCS model atmospheres. We detect lines of 15 heavy elements in
  the spectrum of <ASTROBJ>CS 29491-069</ASTROBJ>, and 18 in <ASTROBJ>HE
  1219-0312</ASTROBJ>; in both cases including the Th II 4019 Å
  line. The heavy-element abundance patterns of these two stars are
  mostly well-matched to scaled solar residual abundances not formed
  by the s-process. We also compare the observed pattern with recent
  high-entropy wind (HEW) calculations, which assume core-collapse
  supernovae of massive stars as the astrophysical environment for the
  r-process, and find good agreement for most lanthanides. The abundance
  ratios of the lighter elements strontium, yttrium, and zirconium, which
  are presumably not formed by the main r-process, are reproduced well by
  the model. Radioactive dating for <ASTROBJ>CS 29491-069</ASTROBJ> with
  the observed thorium and rare-earth element abundance pairs results in
  an average age of 9.5 Gyr, when based on solar r-process residuals, and
  17.6 Gyr, when using HEW model predictions. Chronometry seems to fail
  in the case of <ASTROBJ>HE 1219-0312</ASTROBJ>, resulting in a negative
  age due to its high thorium abundance. <ASTROBJ>HE 1219-0312</ASTROBJ>
  could therefore exhibit an overabundance of the heaviest elements,
  which is sometimes called an “actinide boost”. <P />Based on
  observations collected at the European Southern Observatory, Paranal,
  Chile (Proposal Number 170.D-0010). Table 8 is only available in
  electronic form at http://www.aanda.org

---------------------------------------------------------
Title: CNO Abundances of Hydrogen-Deficient Carbon and R Coronae
Borealis Stars: A View of the Nucleosynthesis in a White Dwarf Merger
Authors: García-Hernández, D. A.; Hinkle, K. H.; Lambert, David. L.;
   Eriksson, K.
2009ApJ...696.1733G    Altcode: 2009arXiv0901.3667G
  We present high-resolution (R ~ 50, 000) observations of near-IR
  transitions of CO and CN of the five known hydrogen-deficient carbon
  (HdC) stars and four R Coronae Borealis (RCB) stars. We perform an
  abundance analysis of these stars by using spectrum synthesis and
  state-of-the-art MARCS model atmospheres for cool hydrogen-deficient
  stars. Our analysis confirms reports by Clayton and colleagues
  that those HdC stars exhibiting CO lines in their spectrum and the
  cool RCB star S Aps are strongly enriched in <SUP>18</SUP>O (with
  <SUP>16</SUP>O/<SUP>18</SUP>O ratios ranging from 0.3 to 16). Nitrogen
  and carbon are in the form of <SUP>14</SUP>N and <SUP>12</SUP>C,
  respectively. Elemental abundances for CNO are obtained from C I,
  C<SUB>2</SUB>, CN, and CO lines. Difficulties in deriving the carbon
  abundance are discussed. Abundances of Na from Na I lines and S from
  S I lines are obtained. Elemental and isotopic CNO abundances suggest
  that HdC and RCB stars may be related objects, and that they probably
  formed from a merger of an He white dwarf with a C-O white dwarf.

---------------------------------------------------------
Title: Calibration of Strömgren uvby-Hβ photometry for late-type
    stars - a model atmosphere approach
Authors: Önehag, A.; Gustafsson, B.; Eriksson, K.; Edvardsson, B.
2009A&A...498..527O    Altcode: 2009A&A...498..527A
  Context: The use of model atmospheres for deriving stellar fundamental
  parameters, such as T_eff, log g, and [Fe/H], will increase as we find
  and explore extreme stellar populations where empirical calibrations
  are not yet available. Moreover, calibrations for upcoming large
  satellite missions of new spectrophotometric indices, similar to the
  uvby-Hβ system, will be needed. <BR />Aims: We aim to test the power
  of theoretical calibrations based on a new generation of MARCS models
  by comparisons with observational photomteric data. <BR />Methods: We
  calculated synthetic uvby-Hβ colour indices from synthetic spectra. A
  sample of 367 field stars, as well as stars in globular clusters, is
  used for a direct comparison of the synthetic indices versus empirical
  data and for scrutinizing the possibilities of theoretical calibrations
  for temperature, metallicity, and gravity. <BR />Results: We show that
  the temperature sensitivity of the synthetic (b-y) colour is very close
  to its empirical counterpart, whereas the temperature scale based upon
  Hβ shows a slight offset. The theoretical metallicity sensitivity of
  the m<SUB>1</SUB> index (and for G-type stars its combination with c_1)
  is somewhat higher than the empirical one, based upon spectroscopic
  determinations. The gravity sensitivity of the synthetic c<SUB>1</SUB>
  index shows satisfactory behaviour when compared to obervations of F
  stars. For stars cooler than the sun, a deviation is significant in the
  c<SUB>1</SUB>-(b-y) diagram. The theoretical calibrations of (b-y),
  (v-y), and c<SUB>1</SUB> seem to work well for Pop II stars and lead
  to effective temperatures for globular cluster stars supporting recent
  claims that atomic diffusion occurs in stars near the turnoff point of
  NGC 6397. <BR />Conclusions: Synthetic colours of stellar atmospheres
  can indeed be used, in many cases, to derive reliable fundamental
  stellar parameters. The deviations seen when compared to observational
  data could be due to incomplete linelists but are possibly also due
  to the effects of assuming plane-parallell or spherical geometry and
  LTE. <P />Model colours are only available in electronic form at the
  CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via
  http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/498/527

---------------------------------------------------------
Title: The dust condensation sequence in red supergiant stars
Authors: Verhoelst, T.; van der Zypen, N.; Hony, S.; Decin, L.; Cami,
   J.; Eriksson, K.
2009A&A...498..127V    Altcode: 2009arXiv0901.1262V
  Context: Red supergiant (RSG) stars exhibit significant mass loss by
  means of a slow, dense wind. They are often considered to be the more
  massive counterparts of Asymptotic Giant Branch (AGB) stars. While AGB
  mass loss is related to their strong pulsations, the RSG are often only
  weakly variable. This raises the question of whether their wind-driving
  mechanism and the dust composition of the wind are the same. <BR />Aims:
  We study the conditions at the base of the wind by determining the
  dust composition of a sample of RSG. The dust composition is assumed
  to be sensitive to the density, temperature, and acceleration at the
  base of the wind. We compare the derived dust composition with the
  composition measured in AGB star winds. <BR />Methods: We compile a
  sample of 27 RSG infrared spectra (ISO-SWS) and supplement these with
  photometric measurements to derive the full spectral energy distribution
  (SED). These data are modelled using a dust radiative-transfer code,
  taking into account the optical properties of the relevant candidate
  materials to search for correlations between mass-loss rate, density
  at the inner edge of the dust shell, and stellar parameters. <BR
  />Results: We find strong correlations between the dust composition,
  mass-loss rate, and the stellar luminosity, roughly in agreement with
  the theoretical dust condensation sequence. We identify the need for
  a continuous (near-)IR dust opacity and tentatively propose amorphous
  carbon, and we note significant differences with AGB star winds in
  terms of the presence of PAHs, absence of “the” 13 μm band, and a
  lack of strong water bands. <BR />Conclusions: Dust condensation in RSG
  is found to experience a freeze-out process that is similar to that in
  AGB stars. Together with the positive effect of the stellar luminosity
  on the mass-loss rate, this suggests that radiation pressure on dust
  grains is an important ingredient in the driving mechanism. Still,
  differences with AGB stars are manifold and thus the winds of RSG
  should be studied individually in further detail.

---------------------------------------------------------
Title: VizieR Online Data Catalog: Calibration of Stromgren phot. for
    late-type stars (Onehag+, 2009)
Authors: Onehag, A.; Gustafsson, B.; Eriksson, K.; Edvardsson, B.
2009yCat..34980527O    Altcode:
  The file "stellar.dat" contains coordinates (J2000) and identifiers
  of the comparison stars. Furthermore the stellar parameters: effective
  temperature (Teff), logarithmic surface gravity (logg), and metallicity
  with respect to the sun ([Fe/H]) are listed. The reddening corrected
  Stromgren indices c1 and m1 and the reddening corrected Stromgren
  (b-y) colours are listed together with the Crawford/Mander H-beta
  indices. <P />The file "model.dat" contains data calculated from the
  MARCS models. The following model parameters are listed: effective
  temperature (Teff), logarithmic surface gravity (logg), and metallicity
  with respect to the sun ([Fe/H]). Synthetic Stromgren indices c1 and
  m1 and synthetic Stromgren (b-y) colours are listed together with the
  synthetic Crawford/Mander H-beta indices. <P />(2 data files).

---------------------------------------------------------
Title: Abundances in bulge stars from high-resolution, near-IR
    spectra. I. The CNO elements observed during the science verification
    of CRIRES at VLT
Authors: Ryde, N.; Edvardsson, B.; Gustafsson, B.; Eriksson, K.;
   Käufl, H. U.; Siebenmorgen, R.; Smette, A.
2009A&A...496..701R    Altcode: 2009arXiv0902.2124R
  Context: The formation and evolution of the Milky Way bulge is not yet
  well understood and its classification is ambiguous. Constraints can,
  however, be obtained by studying the abundances of key elements in
  bulge stars. <BR />Aims: The aim of this study is to determine the
  chemical evolution of C, N, O, and a few other elements in stars in
  the Galactic bulge, and to discuss the sensitivities of the derived
  abundances from molecular lines. <BR />Methods: High-resolution,
  near-infrared spectra in the H band were recorded using the CRIRES
  spectrometer on the Very Large Telescope. Due to the high and variable
  visual extinction in the line-of-sight towards the bulge, an analysis
  in the near-IR is preferred. The C, N, and O abundances can all be
  determined simultaneously from the numerous molecular lines in the
  wavelength range observed. <BR />Results: The three giant stars in
  Baade's window presented here are the first bulge stars observed
  with CRIRES during its science verification observations. We have
  especially determined the C, N, and O abundances, with uncertainties
  of less than 0.20 dex, from CO, CN, and OH lines. Since the systematic
  uncertainties in the derived C, N, and O abundances due to uncertainties
  in the stellar fundamental parameters, notably T_eff, are significant,
  a detailed discussion of the sensitivities of the derived abundances
  is included. We find good agreement between near-IR and optically
  determined O, Ti, Fe, and Si abundances. Two of our stars show a solar
  [C+N/Fe], suggesting that these giants have experienced the first
  dredge-up and that the oxygen abundance should reflect the original
  abundance of the giants. The two giants fit into the picture, in which
  there is no significant difference between the oxygen abundance in bulge
  and thick-disk stars. Our determination of the sulphur abundances is the
  first for bulge stars. The high [S/Fe] values for all the stars indicate
  a high star-formation rate in an early phase of the bulge evolution. <P
  />Based on observations collected at the European Southern Observatory,
  Chile (ESO Programme 60.A-9058A). <P />Table [see full text] is only
  available in electronic from at http://www.aanda.org

---------------------------------------------------------
Title: A new sample of extremely/ultra metal-poor stars
Authors: García Pérez, A. E.; Christlieb, N.; Ryan, S. G.; Beers,
   T. C.; Aoki, W.; Asplund, M.; Barklem, P. S.; Bessell, M. S.; Eriksson,
   K.; Frebel, A.; Gustafsson, B.; Korn, A. J.; Nordström, B.; Norris,
   J. E.
2008PhST..133a4036G    Altcode:
  A sample of 30 very metal-poor stars from the Hamburg-European
  Southern Observatory (ESO) objective-prism survey have been observed
  at high spectral resolution at the Very Large Telescope (VLT) using the
  Ultraviolet and Visual Echelle Spectrograph (UVES). Two of the observed
  stars are very interesting not only because of their very low iron
  content, approximately four orders of magnitude lower than the solar
  value, but also because we detected the neutral lithium resonance line
  at 670.8 nm. Hydrogen lines suggest that the two observed stars have
  effective temperatures around 6000 6250 K and according to isochrones,
  they are either on the main sequence or on the subgiant branch, in
  which case they would probably be the most metal-poor dwarfs or warm
  subgiants with lithium detections known. These detections would allow
  to determine more accurately the slope of the trend of the lithium
  abundance with [Fe/H] than was possible with samples of unevolved
  stars restricted to higher metallicities.

---------------------------------------------------------
Title: CNO abundances in carbon star atmospheres—a progress report
Authors: Eriksson, K.
2008PhST..133a4029E    Altcode:
  A brief progress report is given on an on-going project to estimate the
  C, N and O abundances in carbon stars of the Magellanic Cloud clusters
  NGC 1846 and NGC 419. The changes in these abundances as a function
  of position along the asymptotic giant branch (AGB) are sought for.

---------------------------------------------------------
Title: HE 1327-2326, an Unevolved Star with [Fe/H]&lt;-5.0. II. New
    3D-1D Corrected Abundances from a Very Large Telescope UVES Spectrum
Authors: Frebel, Anna; Collet, Remo; Eriksson, Kjell; Christlieb,
   Norbert; Aoki, Wako
2008ApJ...684..588F    Altcode: 2008arXiv0805.3341F
  We present a new abundance analysis of HE 1327-2326, which is currently
  the most iron-poor star, based on observational data obtained with the
  VLT Ultraviolet and Visual Echelle Spectrograph (UVES). We correct the
  one-dimensional (1D) LTE abundances for three-dimensional (3D) effects
  to provide an abundance pattern that supersedes previous works and
  should be used to observationally test current models of the chemical
  yields of the first-generation supernovae (SNe). Apart from confirming
  the 1D LTE abundances found in previous studies before accounting for 3D
  effects, we make use of a novel technique to apply the 3D-1D corrections
  for CNO which are a function of excitation potential and line strength
  for the molecular lines that comprise the observable CH, NH, and OH
  features. We find that the fit to the NH band at 3360 Å is greatly
  improved due to the application of the 3D-1D corrections. This may
  indicate that 3D effects are actually observable in this star. We also
  report the first detection of several weak Ni lines. The cosmologically
  important element Li is still not detected; the new Li upper limit is
  extremely low, A(Li) &lt; 0.62, and in stark contrast with results not
  only from the Wilkinson Microwave Anisotropy Probe (WMAP) but also
  from other metal-poor stars. We also discuss how the new corrected
  abundance pattern of HE 1327-2326 is being reproduced by individual and
  integrated yields of SNe. <P />Based on observations collected at the
  European Southern Observatory, Paranal, Chile (Proposal ID 075.D-0048).

---------------------------------------------------------
Title: A grid of MARCS model atmospheres for late-type
    stars. I. Methods and general properties
Authors: Gustafsson, B.; Edvardsson, B.; Eriksson, K.; Jørgensen,
   U. G.; Nordlund, Å.; Plez, B.
2008A&A...486..951G    Altcode: 2008arXiv0805.0554G
  Context: In analyses of stellar spectra and colours, and for the
  analysis of integrated light from galaxies, a homogeneous grid
  of model atmospheres of late-type stars and corresponding flux
  spectra is needed. <BR />Aims: We construct an extensive grid of
  spherically-symmetric models (supplemented with plane-parallel ones
  for the highest surface gravities), built on up-to-date atomic and
  molecular data, and make it available for public use. <BR />Methods:
  The most recent version of the MARCS program is used. <BR />Results:
  We present a grid of about 10<SUP>4</SUP> model atmospheres for stars
  with 2500 K ≤ T_eff ≤ 8000 K, -1 ≤ log g = log (GM/R^2) ≤ 5
  (cgs) with various masses and radii, -5 ≤ [Me/H] ≤ +1, with [
  α/Fe] = 0.0 and 0.4 and different choices of C and N abundances. This
  includes “CN-cycled” models with C/N = 4.07 (solar), 1.5 and 0.5,
  C/O ranging from 0.09 to (normally) 5.0 to also represent stars of
  spectral types R, S and N, and with 1.0 ≤ ξ<SUB>t</SUB> ≤ 5 km
  s<SUP>-1</SUP>. We also list thermodynamic quantities (T, P_g, P_e, ρ,
  partial pressures of molecules, etc.) and provide them on the World Wide
  Web, as well as calculated fluxes in approximately 108 000 wavelength
  points. Underlying assumptions in addition to 1D stratification
  (spherical or plane-parallel) include hydrostatic equilibrium,
  mixing-length convection and local thermodynamic equilibrium. We
  discuss a number of general properties of the models, in particular
  in relation to the effects of changing abundances, of blanketing, and
  of sphericity. We illustrate positive and negative feedbacks between
  sphericity and molecular blanketing. We compare the models with those of
  other available grids and find excellent agreement with plane-parallel
  models of Castelli &amp; Kurucz (if convection is treated consistently)
  within the overlapping parameter range. Although there are considerable
  departures from the spherically-symmetric NextGen models, the agreement
  with more recent PHOENIX models is gratifying. <BR />Conclusions: The
  models of the grid show considerable regularities, but some interesting
  departures from general patterns occur for the coolest models due
  to the molecular opacities. We have tested a number of approximate
  “rules of thumb” concerning effects of blanketing and sphericity
  and often found them to be astonishingly accurate. Some interesting
  new phenomena have been discovered and explored, such as the intricate
  coupling between blanketing and sphericity, and the strong effects of
  carbon enhancement on metal-poor models. We give further details of
  line absorption data for molecules, as well as details of models and
  comparisons with observations in subsequent papers.

---------------------------------------------------------
Title: The limb-darkened Arcturus: imaging with the IOTA/IONIC
    interferometer
Authors: Lacour, S.; Meimon, S.; Thiébaut, E.; Perrin, G.; Verhoelst,
   T.; Pedretti, E.; Schuller, P. A.; Mugnier, L.; Monnier, J.; Berger,
   J. P.; Haubois, X.; Poncelet, A.; Le Besnerais, G.; Eriksson, K.;
   Millan-Gabet, R.; Ragland, S.; Lacasse, M.; Traub, W.
2008A&A...485..561L    Altcode: 2008arXiv0804.0192L
  Aims: We undertook an H band interferometric examination of Arcturus,
  a star frequently used as a spatial and spectral calibrator. <BR
  />Methods: Using the IOTA 3 telescope interferometer, we performed
  spectro-interferometric observations (R≈35) of Arcturus. Atmospheric
  models and prescriptions were fitted to the data to derive the
  brightness distribution of the photosphere. Image reconstruction was
  performed using two software algorithms: Wisard and Mira. <BR />Results:
  An achromatic power law proved to be a good model of the brightness
  distribution, with a limb darkening compatible with the one derived
  from atmospheric model simulations using our marcs model. A Rosseland
  diameter of 21.05±0.21 was derived, corresponding to an effective
  temperature of T<SUB>eff</SUB> = 4295±26 K. No companion was detected
  from the closure phases, with an upper limit on the brightness ratio
  of 8×10<SUP>-4</SUP> at 1 AU. The dynamic range at such distance from
  the photosphere was established as 1.5×10<SUP>-4</SUP> (1σ rms). An
  upper limit of 1.7×10<SUP>-3</SUP> was also derived for the level of
  brightness asymmetries present in the photosphere.

---------------------------------------------------------
Title: Intense mass loss from C-rich AGB stars at low metallicity?
Authors: Mattsson, L.; Wahlin, R.; Höfner, S.; Eriksson, K.
2008A&A...484L...5M    Altcode: 2008arXiv0804.2482M
  We argue that the energy injection of pulsations may be of greater
  importance to the mass-loss rate of AGB stars than metallicity, and
  that the mass-loss trend with metallicity is not as simple as sometimes
  assumed. Using our detailed radiation hydrodynamical models that include
  dust formation, we illustrate the effects of pulsation energy on wind
  properties. We find that the mass-loss rate scales with the kinetic
  energy input by pulsations as long as a dust-saturated wind does not
  occur, and all other stellar parameters are kept constant. This includes
  the absolute abundance of condensible carbon (not bound in CO), which
  is more relevant than keeping the C/O-ratio constant when comparing
  stars of different metallicity. The pressure and temperature gradients
  in the atmospheres of stars, become steeper and flatter, respectively,
  when the metallicity is reduced, while the radius where the atmosphere
  becomes opaque is typically associated with a higher gas pressure. This
  effect can be compensated for by adjusting the velocity amplitude of
  the variable inner boundary (piston), which is used to simulate the
  effects of pulsation, to obtain models with comparable kinetic-energy
  input. Hence, it is more relevant to compare models with similar
  energy-injections than of similar velocity amplitude. Since there
  is no evidence for weaker pulsations in low-metallicity AGB stars,
  we conclude that it is unlikely that low-metallicity C-stars have
  lower mass-loss rates, than their more metal-rich counterparts with
  similar stellar parameters, as long as they have a comparable amount
  of condensible carbon.

---------------------------------------------------------
Title: The Giants Stars HE 0107-5240 and HE 0557-4840 and New Searches
    for Metal-Poor Stars
Authors: Christlieb, Norbert; Korn, Andreas J.; Eriksson, Kjell;
   Bessell, Michael S.; Norris, John E.; Keller, Stefan C.; Zhao,
   Yongheng; Zhang, Haotong; Beers, Timothy C.
2008AIPC..990..109C    Altcode:
  We report on a new determination of the iron abundance of HE 0107-5240,
  based on the detection of two Fe II lines in an UV spectrum of the star,
  which yields [Fe/H] = -5.7. Another interesting metal-poor star recently
  discovered with Hamburg/ESO Survey (HES) is HE 0557-4840. With [Fe/H]
  = -4.8, it is the first star located in the “gap” in the metallicity
  distribution function of the galactic halo, in metallicity between the
  two stars known at [Fe/H]&gt;-4.0. HE 0557-4840 is carbon-enhanced
  (i.e., [C/Fe] = +1.7). The abundance ratios of the heavier elements
  are similar to those seen in the majority of the metal-poor stars at
  [Fe/H]&gt;-4.0. <P />We also describe two upcoming wide-angle surveys
  which will be used for searches for metal-poor stars: The Southern Sky
  Survey (SSS), and a stellar survey to be conducted with the Chinese
  LAMOST telescope. These efforts are expected to increase the number
  of known extremely metal-poor stars, including stars below [Fe/H] =
  -5.0, by about two orders of magnitude.

---------------------------------------------------------
Title: On the Use of Blanketed Atmospheres as Boundary Conditions
    for Stellar Evolutionary Models
Authors: VandenBerg, Don A.; Edvardsson, Bengt; Eriksson, Kjell;
   Gustafsson, Bengt
2008ApJ...675..746V    Altcode: 2007arXiv0708.1188V
  Stellar models have been computed for stars having [ Fe/H ]
  = 0.0 (assuming both the Grevesse &amp; Sauval and Asplund et
  al. heavy-element mixtures) and -2.0 to determine the effects on the
  predicted T<SUB>eff</SUB> scale of using boundary conditions derived
  from the latest MARCS model atmospheres. The latter were fitted in a
  fully consistent way to the interior models at the photosphere and at
  τ = 100: the resultant evolutionary sequences on the H-R diagram were
  found to be nearly independent of the chosen fitting point. Tracks
  were also computed in which the pressure at T = T<SUB>eff</SUB> was
  obtained by integrating the hydrostatic equation together with either
  the classical gray T(τ , T<SUB>eff</SUB>) relation or that derived by
  Krishna Swamy from an empirical solar atmosphere. Due to the effects
  of differences in the solar-calibrated values of the mixing-length
  parameter, α<SUB>MLT</SUB>, very similar tracks were obtained for the
  different treatments of the atmosphere, except at solar abundances,
  where the models based on the Krishna Swamy T(τ , T<SUB>eff</SUB>)
  relationship predicted ~150 K hotter giant branches than the others,
  in good agreement with the inferred temperatures of giants in the open
  cluster M67 from recent (V - K) -T<SUB>eff</SUB> relations. Tracks that
  used new “scaled solar, differentially corrected” MARCS atmospheres
  were found to agree well with those that employed the Krishna Swamy
  T(τ , T<SUB>eff</SUB>) relationship, independently of the assumed
  metal abundance. (Gray atmospheres are quite different from MARCS
  models.) Fits of isochrones for [ Fe/H ] = - 2.0 to the CMD of the
  globular cluster M68, as well as the possibility that α<SUB>MLT</SUB>
  varies with stellar parameters, are also discussed.

---------------------------------------------------------
Title: Do R Coronae Borealis stars evolve from white dwarf mergers?
Authors: Lambert, David L.; Kameswara Rao, N.; Hinkle, Kenneth H.;
   Garcia-Hernandez, D. A.; Eriksson, Kjell
2008noao.prop..316L    Altcode:
  Phoenix spectra of C_2, CN and CO lines will provide oxygen isotopic
  abundance ratios (^16O/^17O/^18O) and CNO abundances for cool R Coronae
  Borealis (RCB) stars. The ratios, especially the ^16O/^18O ratio, will
  be used to test the two leading scenarios for RCB production. These
  observations were prompted by Clayton et al.'s striking discovery of
  low ^16O/^18O (&lt;1) ratios for H-deficient carbon (HdC) stars. This
  ratio requires the formation of HdC stars by the merger of two white
  dwarfs as some ^14N is burnt to ^18O. The HdC are possible immediate
  relatives of the RCBs. Yet, our Phoenix observations of the cool RCB
  S Aps give a higher ratio (^16O/^18O=16) than for the HdCs perhaps
  questioning a direct evolutionary connection between HdC and RCB
  stars. Also, our Phoenix CNO abundance analysis of HdCs shows the ^14N
  to ^18O conversion is far from complete. In this proposal, we seek to
  extend our CNO elemental and isotopic abundance analyses from one RCB
  to several in order to explore the evolutionary connection between HdC
  and RCB stars and to constrain the nucleosynthesis that occurs during
  the cannibalism of a He white dwarf by a C-O white dwarf.

---------------------------------------------------------
Title: M 67: a constraint on Z_⊙ and/or on diffusive processes in
    stellar interiors.
Authors: VandenBerg, D. A.; Gustafsson, B.; Edvardsson, B.; Eriksson,
   K.; Ferguson, J. W.
2008MmSAI..79..759V    Altcode:
  The mass of the lowest mass star that has a convective core throughout
  the main-sequence phase is predicted to be a fairly sensitive function
  of Z (especially the CNO abundances). The ∼ 4 Gyr open cluster M 67
  thus provides a constraint on Z_⊙ (and the solar metals mix) because
  (i) it has the same metallicity as the Sun according to high-resolution
  spectroscopy, and (ii) its turnoff stars have masses just above this
  lower mass limit. While isochrones computed for Z = 0.0165, assuming
  the Grevesse &amp; Sauval (1998) heavy-element mixture, are able to
  reproduce the M 67 color-magnitude diagram satisfactorily, those for the
  solar abundances derived by M. Asplund et al. (implying Z_⊙ = 0.0125)
  do not predict a gap near the turnoff where one is observed. These
  results suggest either that there is a problem with the solar metal
  abundances derived by Asplund et al. or that the neglect of diffusive
  processes in the present models is responsible for this difficulty. If
  the latter is the correct explanation, then M 67 provides an important
  constraint on the rates of diffusive processes in the deep interiors
  of stars.

---------------------------------------------------------
Title: HE 0557-4840: Ultra-Metal-Poor and Carbon-Rich
Authors: Norris, John E.; Christlieb, N.; Korn, A. J.; Eriksson, K.;
   Bessell, M. S.; Beers, Timothy C.; Wisotzki, L.; Reimers, D.
2007ApJ...670..774N    Altcode: 2007arXiv0707.2657N
  We report the discovery and high-resolution, high-S/N spectroscopic
  analysis of the ultra-metal-poor red giant HE 0557-4840, which is the
  third most heavy-element-deficient star currently known. Its atmospheric
  parameters are T<SUB>eff</SUB>=4900 K, logg=2.2, and [Fe/H]=-4.75. This
  brings the number of stars with [Fe/H]&lt;-4.0 to three, and the
  discovery of HE 0557-4840 suggests that the metallicity distribution
  function of the Galactic halo does not have a “gap” between
  [Fe/H]=-4.0, where several stars are known, and the two most metal-poor
  stars, at [Fe/H]~-5.3. HE 0557-4840 is carbon rich ([C/Fe]=+1.6), a
  property shared by all three objects with [Fe/H]&lt;-4.0, suggesting
  that the well-known increase of carbon relative to iron with decreasing
  [Fe/H] reaches its logical conclusion (ubiquitous carbon richness) at
  lowest abundance. We also present abundances (nine) and limits (nine)
  for a further 18 elements. For species having well-measured abundances
  or strong upper limits, HE 0557-4840 is “normal” in comparison with
  the bulk of the stellar population at [Fe/H]~-4.0, with the possible
  exception of Co. We discuss the implications of these results for
  chemical enrichment at the earliest times, in the context of single-
  (“mixing and fallback”) and two-component enrichment models. While
  neither offers a clear solution, the latter appears closer to the
  mark. Further data are required to determine the oxygen abundance
  and improve that of Co, and hence more strongly constrain the origin
  of this object. <P />Based on observations collected at ANU's 2.3 m
  telescope on Siding Spring Mountain, Australia, and European Southern
  Observatory, Paranal, Chile (proposal 276.D-5041).

---------------------------------------------------------
Title: Carbon Stars in the Bulge -- or Beyond It?
Authors: Wahlin, R.; Eriksson, K.; Gustafsson, B. >; Ryde, N.;
   Westerlund, B.; Lambert, D. L.
2007ASPC..378..410W    Altcode:
  The carbon stars in the direction of the Bulge were recently proposed
  to belong to the Sagittarius system which, with its lower metallicity,
  would more easily produce carbon stars. The compositions of the carbon
  stars might be used to distinguish between true members of the Bulge and
  members of the Sagittarius stream seen through the Bulge. We present
  oxygen abundances for a sample of carbon stars in the Sagittarius
  dwarf galaxy including its tidal stream, and towards the galactic
  Bulge. The abundances were determined from infrared spectra obtained
  with the ISAAC spectrometer on VLT (R=1500). We find that the oxygen
  abundances of the Bulge carbon stars are compatible with membership
  of the Sagittarius stream, but we also discuss possible scenarios that
  might explain their abundances if they were true Bulge members.

---------------------------------------------------------
Title: Theoretical model atmosphere spectra used for the calibration
    of infrared instruments
Authors: Decin, L.; Eriksson, K.
2007A&A...472.1041D    Altcode: 2007arXiv0708.4120D
  Context: One of the key ingredients in establishing the relation
  between input signal and output flux from a spectrometer is accurate
  determination of the spectrophotometric calibration. In the case
  of spectrometers onboard satellites, the accuracy of this part of
  the calibration pedigree is ultimately linked to the accuracy of
  the set of reference spectral energy distributions (SEDs) that the
  spectrophotometric calibration is built on. <BR />Aims: In this
  paper, we deal with the spectrophotometric calibration of infrared
  (IR) spectrometers onboard satellites in the 2 to 200 μm wavelength
  range. We aim at comparing the different reference SEDs used for the IR
  spectrophotometric calibration. The emphasis is on the reference SEDs
  of stellar standards with spectral type later than A0, with special
  focus on the theoretical model atmosphere spectra. <BR />Methods:
  Using the MARCS model atmosphere code, spectral reference SEDs were
  constructed for a set of IR stellar standards (A dwarfs, solar analogs,
  G9-M0 giants). A detailed error analysis was performed to estimate
  proper uncertainties on the predicted flux values. <BR />Results:
  It is shown that the uncertainty on the predicted fluxes can be
  as high as 10%, but in case high-resolution observational optical
  or near-IR data are available, and IR excess can be excluded, the
  uncertainty on medium-resolution SEDs can be reduced to 1-2% in the
  near-IR, to ~3% in the mid-IR, and to ~5% in the far-IR. Moreover,
  it is argued that theoretical stellar atmosphere spectra are at the
  moment the best representations for the IR fluxes of cool stellar
  standards. <BR />Conclusions: When aiming at a determination of the
  spectrophotometric calibration of IR spectrometers better than 3%,
  effort should be put into constructing an appropriate set of stellar
  reference SEDs based on theoretical atmosphere spectra for some 15
  standard stars with spectral types between A0 V and M0 III.

---------------------------------------------------------
Title: A Constraint on Z<SUB>solar</SUB> from Fits of Isochrones to
    the Color-Magnitude Diagram of M67
Authors: VandenBerg, Don A.; Gustafsson, Bengt; Edvardsson, Bengt;
   Eriksson, Kjell; Ferguson, Jason
2007ApJ...666L.105V    Altcode: 2007arXiv0708.1172V
  The mass at which a transition is made between stars that have radiative
  or convective cores throughout the core H burning phase is a fairly
  sensitive function of Z (particularly, the CNO abundances). As a
  consequence, the ~4 Gyr, open cluster M67 provides a constraint on
  Z<SUB>solar</SUB> (and the solar heavy-element mixture) because (1)
  high-resolution spectroscopy indicates that this system has virtually
  the same metal abundances as the Sun, and (2) its turnoff stars have
  masses just above the lower limit for sustained core convection on
  the main sequence. In this study, evolutionary tracks and isochrones
  using the latest MARCS model atmospheres as boundary conditions have
  been computed for 0.6-1.4 M<SUB>solar</SUB> on the assumption of a
  metals mix (implying Z<SUB>solar</SUB>~0.0125) based on the solar
  abundances derived by M. Asplund and collaborators using 3D model
  atmospheres. These calculations do not predict a turnoff gap where one
  is observed in M67. No such difficulty is found if the analysis uses
  isochrones for Z<SUB>solar</SUB>=0.0165, assuming the Grevesse and
  Sauval mix of heavy elements. Our findings, like the inferences from
  helioseismology, indicate a problem with the abundances of Asplund
  and collaborators. However, it is possible that low-Z models with
  diffusive processes taken into account will be less problematic.

---------------------------------------------------------
Title: The Presence of Diffuse Interstellar Bands in the Spectra of
    Cool Stars
Authors: Destree, Joshua D.; Snow, Theodore P.; Eriksson, Kjell
2007ApJ...664..909D    Altcode:
  Data from the Kitt Peak National Observatory (KPNO) coudé feed
  telescope were used to analyze the strength of three well-known diffuse
  interstellar bands (DIBs; 5780, 5797, and 6614 Å). Ten mid-A, mid-F,
  and mid-G stars with moderate reddening (E<SUB>B-V</SUB>=0.2-1.2) were
  observed, along with one reddened B0 dwarf for comparison. Synthetic
  spectra were calculated to remove the interference of stellar
  features. We report the detection of all three DIBs in A, F, and
  G stars. We also find the correlation of DIB strengths with E(B-V),
  in our sight lines, to be consistent with previous results from Herbig
  (1993), demonstrating that DIB strength is not dependent on the spectral
  type of the target star.

---------------------------------------------------------
Title: On Stellar Models with Blanketed Atmospheres as Boundary
    Conditions
Authors: Vandenberg, Don A.; Edvardsson, Bengt; Eriksson, Kjell;
   Gustafsson, Bengt; Ferguson, Jason W.
2007IAUS..241...23V    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: AGB nucleosynthesis in the Large Magellanic Cloud. Detailed
    abundance analysis of the RV Tauri star MACHO 47.2496.8
Authors: Reyniers, M.; Abia, C.; van Winckel, H.; Lloyd Evans, T.;
   Decin, L.; Eriksson, K.; Pollard, K. R.
2007A&A...461..641R    Altcode: 2006astro.ph.10240R
  Context: Abundance analysis of post-AGB objects as probes of AGB
  nucleosynthesis. <BR />Aims: A detailed photospheric abundance study
  is performed on the carbon-rich post-AGB candidate MACHO 47.2496.8
  in the LMC. <BR />Methods: High-resolution, high signal-to-noise ESO
  VLT-UVES spectra of MACHO 47.2496.8 are analysed by performing detailed
  spectrum synthesis modelling using state-of-the-art carbon-rich MARCS
  atmosphere models. <BR />Results: The spectrum of MACHO 47.2496.8 is
  not only dominated by bands of carbon bearing molecules, but also by
  lines of atomic transitions of s-process elements. The metallicity of
  [Fe/H] = -1.4 is surprisingly low for a field LMC star. The C/O ratio,
  however difficult to quantify, is greater than 2, and the s-process
  enrichment is large: the light s-process elements are enhanced by 1.2
  dex compared to iron ([ls/Fe] = +1.2), while for the heavy s-process
  elements an even stronger enrichment is measured: [hs/Fe] = +2.1. The
  lead abundance is comparable to the [hs/Fe]. With its low intrinsic
  metallicity and its luminosity at the low end of the carbon star
  luminosity function, the star represents likely the final stage of
  a low initial mass star. <BR />Conclusions: .The LMC RV Tauri star
  MACHO 47.2496.8 is highly carbon and s-process enriched, and is most
  probable a genuine post-C(N-type) AGB star. This is the first detailed
  abundance analysis of an extragalactic post-AGB star to date.

---------------------------------------------------------
Title: An abundance study of the most iron-poor star HE1327-2326
    with Subaru/HDS
Authors: Aoki, W.; Frebel, A.; Christlieb, N.; Norris, J. E.; Beers,
   T. C.; Minezaki, T.; Barklem, P. S.; Honda, S.; Takada-Hidai, M.;
   Asplund, M.; Ryan, S. G.; Tsangarides, S.; Eriksson, K.; Steinhauer,
   A.; Deliyannis, C. P.; Nomoto, K.; Fujimoto, M. Y.; Ando, H.; Yoshii,
   Y.; Kajino, T.
2006AIPC..847...53A    Altcode:
  We present an elemental abundance analysis of HE 1327-2326, the most
  iron-deficient star known, based on a comprehensive investigation of
  spectra obtained with the Subaru Telescope. HE 1327-2326 is either
  in its main sequence or subgiant phase of evolution, hence it is
  essentially unevolved. The chemical abundances of this star have
  the following properties, which provide new constraints on models of
  nucleosynthesis processes that occurred in first-generation objects: <P
  />(1)The iron abundance (NLTE) is [Fe/H]= -5.45. This value is 0.2 dex
  lower than that of HE 0107-5240, the previously most iron-poor object
  known. No object having [Fe/H]= -5 ~ -4 is known to date. <P />(2)This
  star, as well as HE 0107-5240, exhibits extremely large overabundances
  of carbon relative to solar ratios ([C/Fe]~ +4). <P />(3)HE 1327-2326
  exhibits remarkable overabundances of the light elements (N, Na, Mg
  and Al), while HE 0107-5240 shows only relatively small excesses of N
  and Na. <P />(4)A large overabundance of Sr is found in HE 1327-2326
  as compared to other extremely low metallicity stars. <P />(5)The Li
  I 6707 Å line, which is detected in the great majority of metal-poor
  dwarfs and warm subgiants, is not found in HE 1327-2326. The upper
  limit on the Li abundance we determine (log ɛ (Li) &lt; 1.5) is
  clearly lower than the expected value from the Spite plateau.

---------------------------------------------------------
Title: Water Vapor on Supergiants: The 12 μm TEXES Spectra of
    μ Cephei
Authors: Ryde, N.; Richter, M. J.; Harper, G. M.; Eriksson, K.;
   Lambert, D. L.
2006ApJ...645..652R    Altcode: 2006astro.ph..3384R
  Several recent papers have argued for warm, semidetached, molecular
  layers surrounding red giant and supergiant stars, a concept known as
  a MOLsphere. Spectroscopic and interferometric analyses have often
  corroborated this general picture. Here we present high-resolution
  spectroscopic data of pure rotational lines of water vapor at 12 μm
  for the supergiant μ Cep. This star has often been used to test the
  concept of molecular layers around supergiants. Given the prediction of
  an isothermal, optically thick water vapor layer in local thermodynamic
  equilibrium around the star (MOLsphere), we expected the 12 μm lines
  to be in emission or at least in absorption but filled in by emission
  from the molecular layer around the star. Our data, however, show the
  contrary; we find definite absorption. Thus, our data do not easily fit
  into the suggested isothermal MOLsphere scenario. The 12 μm lines,
  therefore, put new, strong constraints on the MOLsphere concept and
  on the nature of water seen in signatures across the spectra of early
  M supergiants. We also find that the absorption is even stronger
  than that calculated from a standard, spherically symmetric model
  photosphere without any surrounding layers. A cool model photosphere,
  representing cool outer layers, is, however, able to reproduce the
  lines, but this model does not account for water vapor emission at
  6 μm. Thus, a unified model for water vapor on μ Cep appears to be
  lacking. It does seem necessary to model the underlying photospheres
  of these supergiants in their whole complexity. The strong water vapor
  lines clearly reveal inadequacies of classical model atmospheres.

---------------------------------------------------------
Title: Geometry of giant star model atmospheres: a consistency test
Authors: Heiter, U.; Eriksson, K.
2006A&A...452.1039H    Altcode: 2006astro.ph..3273H
  Aims.We investigate the effect of a geometric inconsistency in the
  calculation of synthetic spectra of giant stars.<BR /> Methods: .Spectra
  computed with model atmospheres calculated in spherical geometry while
  using the plane-parallel approximation for line formation calculations
  (s_p), as well as the fully plane-parallel case (p_p), are compared
  to the consistently spherical case (s_s).<BR /> Results: .We present
  abundance differences for solar metallicity models with T_eff ranging
  from 4000 to 6500 K and log g from 0.5 to 3.0 [cgs]. The effects are
  smaller for s<SUB>p</SUB> calculations (-0.1 dex in the worst case)
  than for the p<SUB>p</SUB> case (up to +0.35 dex for minority species
  and at most -0.04 dex for majority species), both with respect to the
  s<SUB>s</SUB> case. In the s<SUB>p</SUB> case the differences increase
  slightly with temperature, while in the p<SUB>p</SUB> case they show
  a more complex behaviour. In both cases the effects decrease with
  increasing log g and increase with equivalent width.<BR /> Conclusions:
  .Within the parameter range of F, G and K giants, consistency seems
  to be less important than using a spherical model atmosphere. The
  abundance differences due to sphericity effects presented here can be
  used for error estimation in abundance studies relying on plane-parallel
  modelling.

---------------------------------------------------------
Title: HE 1327-2326, an Unevolved Star with [Fe/H]&lt;-5.0. I. A
    Comprehensive Abundance Analysis
Authors: Aoki, W.; Frebel, A.; Christlieb, N.; Norris, J. E.; Beers,
   T. C.; Minezaki, T.; Barklem, P. S.; Honda, S.; Takada-Hidai, M.;
   Asplund, M.; Ryan, S. G.; Tsangarides, S.; Eriksson, K.; Steinhauer,
   A.; Deliyannis, C. P.; Nomoto, K.; Fujimoto, M. Y.; Ando, H.; Yoshii,
   Y.; Kajino, T.
2006ApJ...639..897A    Altcode: 2005astro.ph..9206A
  We present the elemental abundances of HE 1327-2326, the most
  iron-deficient star known, determined from a comprehensive analysis
  of spectra obtained with the Subaru Telescope High Dispersion
  Spectrograph. HE 1327-2326 is either in its main-sequence or
  subgiant phase of evolution. Its non-LTE-corrected iron abundance is
  [Fe/H]=-5.45, 0.2 dex lower than that of HE 0107-5240, the previously
  most iron-poor object known, and more than 1 dex lower than those
  of all other metal-poor stars. Both HE 1327-2326 and HE 0107-5240
  exhibit extremely large overabundances of carbon ([C/Fe]~+4). The
  combination of extremely high carbon abundance with outstandingly
  low iron abundance in these objects clearly distinguishes them from
  other metal-poor stars. The large carbon excesses in these two stars
  are not the result of a selection effect. There also exist important
  differences between HE 1327-2326 and HE 0107-5240. While the former
  shows remarkable overabundances of the light elements (N, Na, Mg,
  and Al), the latter shows only relatively small excesses of N and
  Na. The neutron-capture element Sr is detected in HE 1327-2326,
  but not in HE 0107-5240 its Sr abundance is significantly higher
  than the upper limit for HE 0107-5240. The Li I λ6707 line, which is
  detected in most metal-poor dwarfs and warm subgiants having the same
  temperature as HE 1327-2326, is not found in this object. The upper
  limit of its Li abundance [logɛ(Li)&lt;1.5] is clearly lower than the
  Spite plateau value. These data provide new constraints on models of
  nucleosynthesis processes in the first-generation objects that were
  responsible for metal enrichment at the earliest times. We discuss
  possible scenarios to explain the observed abundance patterns. <P
  />Based on data collected with the Subaru Telescope, which is operated
  by the National Astronomical Observatory of Japan.

---------------------------------------------------------
Title: Amorphous alumina in the extended atmosphere of α Orionis
Authors: Verhoelst, T.; Decin, L.; van Malderen, R.; Hony, S.; Cami,
   J.; Eriksson, K.; Perrin, G.; Deroo, P.; Vandenbussche, B.; Waters,
   L. B. F. M.
2006A&A...447..311V    Altcode: 2005astro.ph.10486V
  In this paper we study the extended atmosphere of the late-type
  supergiant α Orionis. Infrared spectroscopy of red supergiants
  reveals strong molecular bands, some of which do not originate in
  the photosphere but in a cooler layer of molecular material above
  it. Lately, these layers have been spatially resolved by near and
  mid-IR interferometry. In this paper, we try to reconcile the IR
  interferometric and ISO-SWS spectroscopic results on α Orionis with
  a thorough modelling of the photosphere, molecular layer(s) and dust
  shell. From the ISO and near-IR interferometric observations, we find
  that α Orionis has only a very low density water layer close above
  the photosphere. However, mid-IR interferometric observations and a
  narrow-slit N-band spectrum suggest much larger extra-photospheric
  opacity close to the photosphere at those wavelengths, even when
  taking into account the detached dust shell. We argue that this cannot
  be due to the water layer, and that another source of mid-IR opacity
  must be present. We show that this opacity source is probably neither
  molecular nor chromospheric. Rather, we present amorphous alumina
  (Al2O3) as the best candidate and discuss this hypothesis in the
  framework of dust-condensation scenarios.

---------------------------------------------------------
Title: Chemical analysis of carbon stars in the Local Group
Authors: de Laverny, P.; Abia, C.; Domínguez, I.; Plez, B.; Straniero,
   O.; Wahlin, R.; Eriksson, K.; Jørgensen, U. G.
2006A&A...446.1107D    Altcode: 2005astro.ph.10131D
  We present the first results of our ongoing chemical study of carbon
  stars in the Local Group of galaxies. We used spectra obtained with
  UVES at the 8.2 m Kueyen-VLT telescope and a new grid of spherical
  model atmospheres for cool carbon-rich stars which include polyatomic
  opacities, to perform a full chemical analysis of one carbon star, BMB-B
  30, in the Small Magellanic Cloud (SMC) and two, IGI95-C1 and IGI95-C3,
  in the Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. Our main goal
  is to test the dependence on the stellar metallicity of the s-process
  nucleosynthesis and mixing mechanism occurring in AGB stars. For these
  three stars, we find important s-element enhancements with respect
  to the mean metallicity ([M/H]), namely [s/M]≈+1.0, similar to
  the figure found in galactic AGB stars of similar metallicity. The
  abundance ratios derived between elements belonging to the first and
  second s-process abundance peaks, corresponding to nuclei with a magic
  number of neutrons N=50 (88Sr, 89Y, 90Zr) and N=82 (138Ba, 139La, 140Ce,
  141Pr), agree remarkably well with the theoretical predictions of low
  mass (M &lt;3~M_⊙) metal-poor AGB nucleosynthesis models where the
  main source of neutrons is the <SUP>13</SUP>C(α,n)<SUP>16</SUP>O
  reaction activated during the long interpulse phase, in a small
  pocket located within the He-rich intershell. The derived C/O and
  <SUP>12</SUP>C/<SUP>13</SUP>C ratios are, however, more difficult
  to reconcile with theoretical expectations. Possible explanations,
  like the extrinsic origin of the composition of these carbon stars or
  the operation of a non-standard mixing process during the AGB phase
  (such as the cool bottom process), are discussed on the basis of the
  collected observational constraints.

---------------------------------------------------------
Title: Carbon stars in local group dwarf galaxies: C and O abundances
Authors: Wahlin, R.; Eriksson, K.; Gustafsson, B.; Hinkle, K. H.;
   Lambert, D. L.; Ryde, N.; Westerlund, B.
2006MmSAI..77..955W    Altcode: 2006astro.ph..5244W
  We present abundances of carbon and oxygen as well as abundance
  ratios <SUP>12</SUP>C/<SUP>13</SUP>C for a sample of carbon stars
  in the LMC, SMC, Carina, Sculptor and Fornax dwarf galaxies. The
  overall metallicities in these dwarf galaxies are lower than in the
  galactic disc. The observations cover most of the AGB and we discuss
  the abundance patterns in different regions along the AGB. The
  abundances are determined from infrared spectra obtained with the
  ISAAC spectrometer on VLT (R=1500) and the Phoenix Spectrometer on
  Gemini South (R=50000). The synthetic spectra used in the analysis
  were computed with MARCS model atmospheres. We find that the oxygen
  abundance is decreasing with decreasing overall metallicity of the
  system while the C/O ratio at a given evolutionary phase is increasing
  with decreasing oxygen abundance. <P />Based on observations collected
  at the European Southern Observatory, Paranal, Chile (ESO Programme
  70.D-0414 &amp; 072.D-0501)

---------------------------------------------------------
Title: Interferometric Detection of Amorphous Alumina Grains in
    Betelgeuse
Authors: Verhoelst, T.; Decin, L.; Hony, S.; Cami, J.; Eriksson, K.;
   Perrin, G.; Deroo, P.; Vandenbussche, B.; Waters, R.
2006via..conf..361V    Altcode:
  We present a study of the extended atmosphere of the late-type
  supergiant Betelgeuse. From near-IR observations, we find that
  Betelgeuse has only a very low density water layer just above the
  photosphere. However, mid-IR observations suggest a much larger
  opacity source close to the photosphere, which can not be due to the
  water layer. We show that amorphous alumina grains are the most likely
  source of this opacity and discuss this hypothesis in the context of
  dust-condensation scenarios.

---------------------------------------------------------
Title: A strongly s-process enriched  RV Tauri star in the LMC.
Authors: Reyniers, M.; Abia, C.; Van Winckel, H.; Lloyd Evans, T.;
   Decin, L.; Eriksson, K.
2006MmSAI..77..949R    Altcode:
  A detailed abundance analysis is presented of an intriguing object in
  the Large Magellanic Cloud that links the class of RV Tauri stars to the
  post-AGB phase of evolution: MACHO 47.2496.8. The spectrum, taken with
  VLT-UVES, is dominated by molecular lines of carbon bearing molecules,
  together with strong transitions of s-process species. Detailed
  spectral syntheses were made using a state-of-the-art carbon rich
  MARCS model. A surprisingly low metallicity ([Fe/H] = -1.4), together
  with strong carbon (C/O&gt;2) and s-process overabundances were found,
  reaching values of [ls/Fe] = +1.2 for the light s-process elements,
  and even [hs/Fe] = +2.1 for the heavy ones. The strong s-process
  enhancements are in agreement with the theoretical expectations at
  that metallicity. Only the combination of a low lead content and a
  high [hs/ls] is not easily explained by the current nucleosynthetic
  models. It is not clear whether this star is intrisically or
  extrinsically enriched, but several arguments favour an intrisic
  enrichment, implying the object to be a genuine post carbon (N-type)
  AGB star. With the low metallicity and a luminosity at the very low
  end of the carbon star luminosity function, MACHO 47.2496.8 represents
  the final evolutionary state of a star of low initial mass. <P />Based
  on observations collected at ESO, Chile (programme 074.D-0619(A))

---------------------------------------------------------
Title: Is Arcturus a well-understood K giant?. Test of model
    atmospheres and potential companion detection by near-infrared
    interferometry
Authors: Verhoelst, T.; Bordé, P. J.; Perrin, G.; Decin, L.; Eriksson,
   K.; Ridgway, S. T.; Schuller, P. A.; Traub, W. A.; Millan-Gabet, R.;
   Lacasse, M. G.; Waelkens, C.
2005A&A...435..289V    Altcode: 2005astro.ph..1669V
  We present near-IR interferometric measurements of the K1.5 giant
  Arcturus (α Bootis), obtained at the IOTA interferometer with the FLUOR
  instrument, in four narrow filters with central wavelengths ranging
  from 2.03 μm to 2.39 μm. These observations were expected to allow
  us to quantify the wavelength dependence of the diameter of a typical
  K giant. They are compared to predictions from both plane-parallel and
  spherical model atmospheres. Unexpectedly, neither can explain the
  observed visibilities. We show that these data suggest the presence
  of a companion, in accordance with the Hipparcos data on this star,
  and discuss this solution with respect to Arcturus' single star status.

---------------------------------------------------------
Title: Nucleosynthetic signatures of the first stars
Authors: Frebel, Anna; Aoki, Wako; Christlieb, Norbert; Ando, Hiroyasu;
   Asplund, Martin; Barklem, Paul S.; Beers, Timothy C.; Eriksson,
   Kjell; Fechner, Cora; Fujimoto, Masayuki Y.; Honda, Satoshi; Kajino,
   Toshitaka; Minezaki, Takeo; Nomoto, Ken'ichi; Norris, John E.; Ryan,
   Sean G.; Takada-Hidai, Masahide; Tsangarides, Stelios; Yoshii, Yuzuru
2005Natur.434..871F    Altcode: 2005astro.ph..3021F
  The chemically most primitive stars provide constraints on the nature
  of the first stellar objects that formed in the Universe; elements
  other than hydrogen, helium and traces of lithium present within
  these objects were generated by nucleosynthesis in the very first
  stars. The relative abundances of elements in the surviving primitive
  stars reflect the masses of the first stars, because the pathways of
  nucleosynthesis are quite sensitive to stellar masses. Several models
  have been suggested to explain the origin of the abundance pattern
  of the giant star HE0107-5240, which hitherto exhibited the highest
  deficiency of heavy elements known. Here we report the discovery of
  HE1327-2326, a subgiant or main-sequence star with an iron abundance
  about a factor of two lower than that of HE0107-5240. Both stars
  show extreme overabundances of carbon and nitrogen with respect to
  iron, suggesting a similar origin of the abundance patterns. The
  unexpectedly low Li and high Sr abundances of HE1327-2326, however,
  challenge existing theoretical understanding: no model predicts the
  high Sr abundance or provides a Li depletion mechanism consistent with
  data available for the most metal-poor stars.

---------------------------------------------------------
Title: Carbon stars in local group dwarf galaxies: C &amp;
    O abundances
Authors: Wahlin, R.; Eriksson, K.; Gustafsson, B.; Hinkle, K. H.;
   Lambert, D. L.; Ryde, N.; Westerlund, B.
2005ESASP.560.1017W    Altcode: 2005csss...13.1017W
  No abstract at ADS

---------------------------------------------------------
Title: Phoenix Spectra of Carbon Stars in the LMC
Authors: Wahlin, Rurik; Eriksson, Kjell; Gustafsson, Bengt; Hinkle,
   Kenneth; Lambert, David; Ryde, Nils; Westerlund, Bengt
2005hris.conf..439W    Altcode:
  We present high-resolution, IR-spectra of Carbon stars in the LMC
  obtained with the Phoenix spectrometer on the Gemini South 8-meter
  telescope. This is part of an ongoing project where CNO abundances
  and 12C/13C ratios of Carbon Stars are determined in Local-Group
  dwarf galaxies of different metallicities. The spectra obtained so
  far cover two 20 cm 1 wide spectral regions in the H and K bands. The
  bands contain lines from CN, C2, and CO, with 12C and 13C isotopes, and
  several atomic lines. The spectra are analyzed with synthetic spectra
  of model atmospheres from the MARCS spherical-model-atmosphere code.

---------------------------------------------------------
Title: The new record holder for the most iron-poor star: HE 1327
    2326, a dwarf or subgiant with [Fe/H[=[minus sign]5.4
Authors: Frebel, A.; Aoki, W.; Christlieb, N.; Ando, H.; Asplund, M.;
   Barklem, P. S.; Beers, T. C.; Eriksson, K.; Fechner, C.; Fujimoto,
   M. Y.; Honda, S.; Kajino, T.; Minezaki, T.; Nomoto, K.; Norris, J. E.;
   Ryan, S. G.; Takada-Hidai, M.; Tsangarides, S.; Yoshii, Y.
2005IAUS..228..207F    Altcode: 2005astro.ph..9658F
  We describe the discovery of HE 1327-2326, a dwarf or subgiant with
  [Fe/H]=-5.4. The star was found in a sample of bright metal-poor
  stars selected from the Hamburg/ESO survey. Its abundance pattern is
  characterized by very high C and N abundances. The detection of Sr
  which is overabundant by a factor of 10 as compared to iron and the
  Sun, suggests that neutron-capture elements had already been produced
  in the very early Galaxy. A puzzling Li depletion is observed in this
  unevolved star which contradicts the value of the primordial Li derived
  from WMAP and other Li studies. Possible scenarios for the origin of
  the abundance pattern (Pop. II or Pop. III) are presented as well as
  an outlook on future observations.

---------------------------------------------------------
Title: The Abundance of Elements in Cool Stars, as Determined from
    High-Resolution 1 5 μm Spectroscopy
Authors: Ryde, Nils; Gustafsson, Bengt; Eriksson, Kjell; Wahlin, Rurik
2005hris.conf..365R    Altcode: 2004astro.ph..7340R
  We review the field of abundance determinations of elements in cool
  stars, with special interest paid to determinations based on analyses
  of high-resolution, 1 5 μm spectra. We discuss the current status,
  problems, and challenges of exploring high-resolution, near-infrared
  spectra. In particular, advantages and drawbacks are pointed out. A few
  examples of current, chemical-abundance determinations are highlighted
  and, finally, we discuss the development and future prospects of
  the field.

---------------------------------------------------------
Title: Abundances of s-elements in Extragalactic Carbon Stars
Authors: de Laverny, P.; Abia, C.; Domínguez, I.; Plez, B.; Straniero,
   O.; Wahlin, R.; Eriksson, K.; Jørgensen, U. G.
2005IAUS..228..533D    Altcode:
  Carbon stars found in the Small Magellanic Cloud and the Sagittarius
  Dwarf Spheroidal galaxy have been chemically analysed. We found
  that the abundance ratios derived between elements belonging to the
  first and the second s-process abundance peaks agree remarkably
  well with the theoretical predictions of low mass metal-poor AGB
  nucleosynthesis models. Together with their estimated luminosities,
  their derived abundances and their carbon isotopic ratio we speculate
  on the evolutionary status of these carbon stars.

---------------------------------------------------------
Title: ISO-SWS calibration and the accurate modelling of cool-star
    atmospheres.  IV. G9 to M2 stars
Authors: Decin, L.; Vandenbussche, B.; Waelkens, C.; Decin, G.;
   Eriksson, K.; Gustafsson, B.; Plez, B.; Sauval, A. J.
2003A&A...400..709D    Altcode: 2002astro.ph..7653D
  A detailed spectroscopic study of 11 giants with spectral type
  from G9 to M2 is presented. The 2.38-4.08 mu m wavelength-range of
  band 1 of ISO-SWS (Short-Wavelength Spectrometers on board of the
  Infrared Space Observatory) in which many different molecules -
  with their own dependence on each of the stellar parameters - are
  absorbing, enables us to estimate the effective temperature, the
  gravity, the microturbulence, the metallicity, the CNO-abundances,
  the <SUP>12</SUP>C/<SUP>13</SUP>C-ratio and the angular diameter from
  the ISO-SWS data. Using the Hipparcos' parallax, the radius, luminosity
  and gravity-inferred mass are derived. The stellar parameters obtained
  are in good agreement with other published values, though also some
  discrepancies with values deduced by other authors are noted. For a
  few stars (delta Dra, xi Dra, alpha Tuc, H Sco and alpha Cet) some
  parameters - e.g. the CNO-abundances - are derived for the first
  time. By examining the correspondence between different ISO-SWS
  observations of the same object and between the ISO-SWS data and
  the corresponding synthetic spectrum, it is shown that the relative
  accuracy of ISO-SWS in band 1 (2.38-4.08 mu m) is better than 2%
  for these high-flux sources. The high level of correspondence between
  observations and theoretical predictions, together with a confrontation
  of the estimated T<SUB>eff</SUB> (ISO) value with T<SUB>eff</SUB> values
  derived from colours - which demonstrates the consistency between V-K,
  BC<SUB>K</SUB>, T<SUB>eff</SUB> and theta<SUB>d</SUB> derived from
  optical or IR data - proves that both the used MARCS models to derive
  the stellar quantities and the flux calibration of the ISO-SWS detectors
  have reached a high level of reliability. <P />Based on observations
  with ISO, an ESA project with instruments funded by ESA Member States
  (especially the PI countries France, Germany, The Netherlands and the
  UK) and with the participation of ISAS and NASA. <P />Appendices A-D
  are only available in electronic form at http://www.edpsciences.org

---------------------------------------------------------
Title: ISO-SWS calibration and the accurate modelling of cool-star
    atmospheres.  II. General results
Authors: Decin, L.; Vandenbussche, B.; Waelkens, C.; Eriksson, K.;
   Gustafsson, B.; Plez, B.; Sauval, A. J.; Hinkle, K.
2003A&A...400..679D    Altcode: 2002astro.ph..7621D
  The fine calibration of the ISO-SWS detectors (Infrared Space
  Observatory - Short Wavelength Spectrometer) has proven to be a delicate
  problem. We therefore present a detailed spectroscopic study in the
  2.38-12 mu m wavelength range of a sample of 16 A0-M2 stars used for
  the calibration of ISO-SWS. By investigating the discrepancies between
  the ISO-SWS data of these sources, the theoretical predictions of their
  spectra, the high-resolution FTS-KP (Kitt Peak) spectrum of alpha Boo
  and the solar FTS-ATMOS (Atmospheric Trace Molecule Spectroscopy)
  spectrum, both calibration problems and problems in computing the
  theoretical models and the synthetic spectra are revealed. The
  underlying reasons for these problems are sought for and the impact
  on the further calibration of ISO-SWS and on the theoretical modelling
  is discussed extensively. <P />Based on observations with ISO, an ESA
  project with instruments funded by ESA Member States (especially the
  PI countries France, Germany, The Netherlands and the UK) and with
  the participation of ISAS and NASA. <P />Appendix is only available
  in electronic form at http://www.edpsciences.org

---------------------------------------------------------
Title: Imaging polarimetry of stellar light scattered in detached
    shells around the carbon stars R Scl and U Ant
Authors: González Delgado, D.; Olofsson, H.; Schwarz, H. E.; Eriksson,
   K.; Gustafsson, B.; Gledhill, T.
2003A&A...399.1021G    Altcode:
  Imaging polarimetry has been used to study the extended, detached
  circumstellar shells around the bright carbon stars <ASTROBJ>R
  Scl</ASTROBJ> and <ASTROBJ>U Ant</ASTROBJ>. The observations were
  done in two narrow band filters centred on the resonance lines of
  neutral K and Na, but much broader than the expected line widths. The
  polarimetric data reveal brightness distributions, in both cases,
  which are in perfect agreement with previous observations of scattered
  light obtained through direct imaging techniques. The total intensity
  images towards <ASTROBJ>R Scl</ASTROBJ> outline, in both filters,
  circular disk-like distributions out to a radius of ~21arcsec , where
  the intensity drops sharply. The polarised intensity images reveal,
  however, that the scattering occurs in a geometrically thin shell. The
  degree of polarisation reaches values of ~35% in both filters. The
  imaging polarimetry observations of <ASTROBJ>U Ant</ASTROBJ> reveal a
  somewhat more complex structure, where the existence of several shells
  can be discerned. The polarised scattered light comes from a component,
  at a radius of ~50arcsec from the star, which lies outside the region
  where the bulk of the light is scattered. The latter comes from a
  dominating shell at ~43arcsec , which coincides spatially with the
  detached gas shell inferred from CO radio line data, and there may be
  another two shells inside this. The polarisation degree reaches ~50%
  in the outer component. We model, with a code based on the Monte Carlo
  method, the scattered emission under the assumption of dust scattering,
  using the observed polarised brightness distributions as constraints. In
  the case of <ASTROBJ>R Scl</ASTROBJ> we found that the polarised, as
  well as the total, light distributions can be explained by scattering
  in a 2arcsec wide shell of radius 20arcsec containing a dust mass of
  ~2*E<SUP>-6</SUP> M<SUB>sun</SUB>. This dust shell is also responsible
  for the thermal dust emission measured by IRAS. There is room, up to 30%
  of the total scattered flux, for other scattering agents. Comparison
  with CO radio line data shows that this dust shell probably lies outside
  the detached CO gas shell. In the case of <ASTROBJ>U Ant</ASTROBJ> the
  modelling explains the outer component in terms of a 5arcsec wide shell
  at a radius of about 52arcsec with a dust mass of ~4*E<SUP>-6</SUP>
  M<SUB>sun</SUB>. This is also the dust shell responsible for the
  emission measured by IRAS. However, the bulk of the scattered light
  cannot in this case be due to scattering by dust. In accordance
  with a discussion in a previous paper we attribute the remaining,
  unpolarised, scattering to the KI and Na D resonance lines. In both
  cases we found evidence that a dust shell has separated from the rest
  of the circumstellar medium. This may be due to gas-grain drift,
  or to hydrodynamical effects, which may also explain the complex
  multiple-shell structure seen towards <ASTROBJ>U Ant</ASTROBJ>. The
  model results are very dependent on the grain size distribution,
  and the observational data can only be reconciled with a very steep
  decline in grain size. <P />Based on observations using the 3.6 m
  telescope of the European Southern Observatory, La Silla, Chile.

---------------------------------------------------------
Title: Carbon Stars in the Local Group -- Detailed Abundance Analysis
    of Carbon Stars in the LMC
Authors: Lambert, David L.; Eriksson, Kjell; Gustafsson, Bengt;
   Hinkle, Kenneth H.; Ryde, Nils; Wahlin, Rurik; Westerlund, Bengt
2003noao.prop..265L    Altcode:
  Using the Phoenix on Gemini we propose to observe a sample of carbon
  stars in the LMC in four different wavelength regions at high spectral
  resolution and with high S/N. The spectra will provide CO, CN, and
  C_2 and atomic lines from which elemental and isotopic C, N, and O
  abundances and metal abundances will be derived by an approach similar
  to that previously used for Galactic field carbon stars (Lambert et
  al. 1986). We will then be able to calibrate lower resolution spectra
  of carbon stars in other Local Group galaxies. The observational study
  of carbon stars is a key to understanding late evolutionary stages
  and nucleosynthesis of low mass stars.

---------------------------------------------------------
Title: The Infrared Spectrum of R Doradus
Authors: Ryde, N.; Eriksson, K.
2003IAUS..210P.E53R    Altcode: 2002astro.ph.10188R
  Here, we present our modelling (Ryde &amp; Eriksson, 2002 A&amp;A 386,
  874) of the 2.6-3.7 micron spectrum of the red semiregular variable R
  Doradus observed with the Short-Wavelength Spectrometer on board the
  Infrared Space Observatory. We will also present the entire spectrum
  of R Dor up to 5 microns based on our model photosphere in order to
  show which molecules are important for the emergent spectrum.

---------------------------------------------------------
Title: A Grid of Model Atmospheres for Cool Stars
Authors: Gustafsson, B.; Edvardsson, B.; Eriksson, K.; Mizuno-Wiedner,
   M.; Jørgensen, U. G.; Plez, B.
2003ASPC..288..331G    Altcode: 2003sam..conf..331G
  An extensive grid of spherically symmetric model atmospheres of stars
  with <P />1. 2500 K ≤ T<SUB>eff</SUB> ≤ 8000 K, 2. -1.0 ≤ log g
  (= log GM/R<SUP>2</SUP>) ≤ 5.0 (cgs units), 3. different combinations
  of M and R, 4. -5 ≤ [A/H] ≤ 1, and 5. a number of CNO abundance
  combinations <P />is being constructed with an updated version of the
  MARCS program. <P />Special efforts are made to reach accuracy and
  completeness in opacity data. Opacity sampling is used with 10,000
  and (for a minority of models) 90,000 wavelength points. Synthetic
  spectra are also provided. <P />We shall show how these classical
  models may be used to illustrate important physical properties of cool
  star atmospheres.

---------------------------------------------------------
Title: A New MARCS Grid
Authors: Gustafsson, B.; Edvardsson, B.; Eriksson, K.; Jørgensen,
   U. G.; Mizuno-Wiedner, M.; Plez, B.
2003IAUS..210P..A4G    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A MARCS Grid of S-Type Star Atmospheres
Authors: Plez, B.; van Eck, S.; Jorissen, A.; Edvardsson, B.; Eriksson,
   K.; Gustafsson, B.
2003IAUS..210P..A2P    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The 3 mu m spectrum of R Doradus observed with the ISO-SWS
Authors: Ryde, N.; Eriksson, K.
2002A&A...386..874R    Altcode: 2002astro.ph..2171R
  We have modeled the 2.6-3.7 μm spectrum of the red semiregular
  variable R Doradus observed with the Short-Wavelength Spectrometer on
  board the Infrared Space Observatory. The wavelength resolution of
  the observations varies between R ~ 2000-2500. We have calculated a
  synthetic spectrum using a hydrostatic model photosphere in spherical
  geometry. The agreement between the synthetic spectrum and the ISO
  observations is encouraging, especially in the wavelength region
  of 2.8-3.7 μm, suggesting that a hydrostatic model photosphere is
  adequate for the calculation of synthetic spectra in the near infrared
  for this moderately varying red giant star. However, an additional
  absorption component is needed at 2.6-2.8 μm and this discrepancy is
  discussed. The spectral signatures are dominated by water vapour in the
  stellar photosphere, but several photospheric OH, CO, and SiO features
  are also present. The effective temperature and surface gravity derived
  for R Dor, based on the 2.6-3.7 μm ISO spectrum and the modeling of
  it with a hydrostatic model photosphere, are 3000+/- 100 K and log g =
  0 +/- 1 (cgs), respectively. The spectral region observed is found to be
  temperature sensitive. The effective temperature given here is slightly
  higher than those reported in the literature. We also discuss possible
  reasons for this. Based on observations with ISO, an ESA project with
  instruments funded by ESA Member States (especially the PI countries:
  France, Germany, The Netherlands and the UK) and with the participation
  of ISAS and NASA. The SWS is a joint project of SRON and MPE.

---------------------------------------------------------
Title: Imaging of detached shells around the carbon stars <ASTROBJ>R
    Scl</ASTROBJ> and <ASTROBJ>U Ant</ASTROBJ> through scattered
    stellar light
Authors: González Delgado, D.; Olofsson, H.; Schwarz, H. E.; Eriksson,
   K.; Gustafsson, B.
2001A&A...372..885G    Altcode: 2001astro.ph..4140G; 2001astro.ph..4140D
  We present the first optical images of scattered light from large,
  detached gas/dust shells around two carbon stars, <ASTROBJ>R
  Scl</ASTROBJ> and <ASTROBJ>U Ant</ASTROBJ>, obtained in narrow band
  filters centred on the resonance lines of neutral K and Na, and in
  a Ström}gren b filter (only <ASTROBJ>U Ant</ASTROBJ>). They confirm
  results obtained in CO radio line observations, but also reveal new
  and interesting structures. Towards <ASTROBJ>R Scl</ASTROBJ> the
  scattering appears optically thick in both the K and Na filters, and
  both images outline almost perfectly circular disks with essentially
  uniform intensity out to a sharp outer radius of ~21arcsec . These
  disks are larger - by about a factor of two - than the radius of the
  detached shell which has been marginally resolved in CO radio line
  data. In <ASTROBJ>U Ant</ASTROBJ> the scattering in the K filter
  appears to be, at least partially, optically thin, and the image is
  consistent with scattering in a geometrically thin (~3arcsec ) shell
  (radius ~43arcsec ) with an overall spherical symmetry. The size of
  this shell agrees very well with that of the detached shell seen in
  CO radio line emission. The scattering in the Na filter appears more
  optically thick, and the image suggests the presence of at least one,
  possibly two, shells inside the 43arcsec shell. There is no evidence
  for such a multiple-shell structure in the CO data, but this can be due
  to considerably lower masses for these inner shells. Weak scattering
  appears also in a shell which is located outside the 43arcsec shell. The
  present data do not allow us to conclusively identify the scattering
  agent, but we argue that most of the emission in the K and Na filter
  images is to due to resonance line scattering, and that there is
  also a weaker contribution from dust scattering in the <ASTROBJ>U
  Ant</ASTROBJ> data. Awaiting new observational data, our interpretation
  must be regarded as tentative. Based on observations using the 3.6 m
  telescope of the European Southern Observatory, La Silla, Chile.

---------------------------------------------------------
Title: Images in Scattered Light of Two Carbon Stars (CD-ROM
Directory: contribs/gonzalez)
Authors: González Delgado, D.; Olofsson, H.; Schwarz, H.; Eriksson,
   K.; Gustafsson, B.
2001ASPC..223.1219G    Altcode: 2001csss...11.1219G
  No abstract at ADS

---------------------------------------------------------
Title: ISO-SWS calibration and the accurate modelling of cool-star
    atmospheres. I. Method
Authors: Decin, L.; Waelkens, C.; Eriksson, K.; Gustafsson, B.; Plez,
   B.; Sauval, A. J.; Van Assche, W.; Vandenbussche, B.
2000A&A...364..137D    Altcode: 2000astro.ph..8316D
  A detailed spectroscopic study of the ISO-SWS data of the red
  giant alpha Tau is presented, which enables not only the accurate
  determination of the stellar parameters of alpha Tau, but also serves
  as a critical review of the ISO-SWS calibration. This study is situated
  in a broader context of an iterative process in which both accurate
  observations of stellar templates and cool star atmosphere models
  are involved to improve the ISO-SWS calibration process as well as the
  theoretical modelling of stellar atmospheres. Therefore a sample of cool
  stars, covering the whole A0 - M8 spectral classification, has been
  observed in order to disentangle calibration problems and problems
  in generating the theoretical models and corresponding synthetic
  spectrum. By using stellar parameters found in the literature large
  discrepancies were seen between the ISO-SWS data and the generated
  synthetic spectrum of alpha Tau. A study of the influence of various
  stellar parameters on the theoretical models and synthetic spectra,
  in conjunction with the Kolmogorov-Smirnov test to evaluate objectively
  the goodness-of-fit, enables us to pin down the stellar parameters with
  a high accuracy: T<SUB>eff</SUB> = 3850 +/- 70 K, log g = 1.50 +/- 0.15,
  M = 2.3 +/- 0.8 M<SUB>sun</SUB>, z = -0.15 +/- 0.20 dex, xi<SUB>t</SUB>
  = 1.7 +/- 0.3 km s<SUP>-1</SUP>, <SUP>12</SUP>C/<SUP>13</SUP>C = 10
  +/- 1, varepsilon (C) = 8.35 +/- 0.20 dex, varepsilon (N) = 8.35 +/-
  0.25 dex, varepsilon (O) = 8.83 +/- 0.15 dex and theta<SUB>d</SUB> =
  20.77 +/- 0.83 mas. These atmospheric parameters were then compared
  with the results provided by other authors using other methods
  and/or spectra. Based on observations with ISO, an ESA project with
  instruments funded by ESA Member States (especially the PI countries
  France, Germany, the Netherlands and the United Kingdom) and with the
  participation of ISAS and NASA.

---------------------------------------------------------
Title: Mira's Wind Explored in Scattering Infrared CO Lines
Authors: Ryde, N.; Gustafsson, B.; Eriksson, K.; Hinkle, K. H.
2000ApJ...545..945R    Altcode: 2000astro.ph..8235R
  We have observed the intermediate regions of the circumstellar
  envelope of Mira (ο Ceti) in photospheric light scattered by three
  vibration-rotation transitions of the fundamental band of CO, from
  low-excited rotational levels of the ground vibrational state, at an
  angular distance of β~2<SUP>”</SUP>-7" away from the star. The data
  were obtained with the Phoenix spectrometer mounted on the 4 m Mayall
  telescope at Kitt Peak. The spatial resolution is approximately 0.5"
  and seeing limited. Our observations provide absolute fluxes, leading
  to an independent new estimate of the mass-loss rate of approximately
  3×10<SUP>-7</SUP> M<SUB>solar</SUB> yr<SUP>-1</SUP>, as derived from
  a simple analytic wind model. We find that the scattered intensity
  from the wind of Mira for 2<SUP>”</SUP>&lt;~β&lt;~7<SUP>”</SUP>
  decreases as β<SUP>-3</SUP>, which suggests a time constant mass-loss
  rate, when averaged over 100 yr, over the past 1200 yr.

---------------------------------------------------------
Title: ISO Impact on Stellar Models and Viceversa
Authors: Decin, L.; Waelkens, C.; Eriksson, K.; Gustafsson, B.; Plez,
   B.; Sauval, A. J.; van Assche, W.; Vandenbussche, B.
2000ESASP.456..289D    Altcode: 2000astro.ph..8362D; 2000ibp..conf..289D
  We present a detailed spectroscopic study of a sample of bright,
  mostly cool, stars observed with the Short-Wavelength Spectrometer
  (SWS) on board ISO, which enables the accurate determination of the
  stellar parameters of the cool giants, but also serves as a critical
  review of the ISO-SWS calibration.

---------------------------------------------------------
Title: Gasdynamics of Detached Shells Around Carbon Stars With
    Variable Mass Loss
Authors: Myasnikov, A. V.; Belov, N. A.; Gustafsson, B.; Eriksson, K.
2000Ap&SS.274..231M    Altcode:
  Gasdynamic features of detached shells around carbon stars with
  variable mass loss rate are investigated in detail numerically. It
  is shown that a shell is unstable and also, 2D perturbations are less
  developed that 3D ones. The structure of perturbed flows corresponding
  to different evolution scenarios is compared. The results obtained
  seem to be promising for interpretation of observations, in particular,
  the recently obtained detailed data of TT Cyg.

---------------------------------------------------------
Title: CO Imaging of Late-Type Circumstellar Shells
Authors: Gustafsson, Bengt; Eriksson, Kjell; Lambert, David L.;
   Olofsson, Hans; Ryde, Nils; Schoier, Fredrik L.
2000noao.prop..293G    Altcode:
  Microwave emission lines and optical resonance lines have been used
  to image circumstellar shells on the sky. Now it is possible to
  image resonance scattering from infrared vibration-rotational carbon
  monoxide lines (see Ryde et al. A&amp; A 347, L35, 1999). Infrared CO is
  formed closer to the star than microwave CO and provides complementary
  information. Infrared CO mapping is especially powerful because many
  CO lines of differing excitation are present, allowing the extraction
  of excitation temperature and abundance from the measured column
  densities. Previous on-star observations have led to the detection
  of multiple velocity components in the CO lines, formed in different
  parts of the circumstellar shell. We have found in an earlier observing
  run with this method that the shell of CO gas around Mira (4 arcsec-10
  arcsec from the star) is spherically symmetric and homogeneous. But we
  also trace from the data a region close to the star devoid of gas or
  at least of CO (Ryde et al. ApJ, soon to be submitted). Each CO line
  can be used to image the circumstellar outflow at different stellar
  radii. Information on the velocity structure and the development of
  clumps in the flow will be extracted. The present proposal focuses on
  the study of shells around carbon stars for which we have complementary
  mm and optical data. We will furthermore for the first time map detached
  shells with this method.

---------------------------------------------------------
Title: Interferometric Molecular Line observations of RW LMi
Authors: Lindqvist, Michael; Lucas, Robert; Olofsson, Hans; Larsen,
   Fredrick; Omont, Alain; Eriksson, Kjell; Gustafsson, Bengt
2000IAUS..177..557L    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: VizieR Online Data Catalog: Atmospheric parameters in
    metal-poor stars. II (Gratton+, 1999)
Authors: Gratton, R. G.; Carretta, E.; Eriksson, K.; Gustafsson, B.
2000yCat..33500955G    Altcode:
  We present non-LTE corrections to abundances of Fe, O, Na, and Mg
  derived from LTE analyses of F-K stars over a broad range of gravities
  and metal abundances; they were obtained using statistical equilibrium
  calculations and new model atoms. Line opacity was considered by
  means of an empirical procedure where it was attributed to a veil
  of weak Fe I lines; in the case of solar-type dwarfs, results were
  compared with those obtained using (LTE) mean intensities computed
  from OSMARCS models. We think that the empirical procedure produces
  better results for metal-poor stars, while mean intensities should
  perhaps be preferred for the Sun (where departures from LTE are
  anyway not very large). Collisions with both electrons and H I atoms
  were considered. Since cross sections for this second mechanism
  are very poorly known, we calibrated them empirically by matching
  observations of RR Lyrae variables at minimum light (discussed in
  Clementini et al., 1995, Cat. ). These stars were selected because
  non-LTE effects are expected to be larger in these stars than in
  those usually considered in the study of the chemical evolution of the
  Galaxy (cool main sequence and red giant branch stars). We found that
  different non-LTE mechanisms are important for the different species
  and transitions considered; on the whole, our calculations yielded
  moderate corrections to LTE abundances for high excitation O lines
  in warm dwarfs and giants, Na and Mg lines in giants and supergiants,
  and Fe I lines in F-supergiants (where corrections becomes very large
  for IR O lines). Non-LTE corrections were found to be negligible in
  the other cases studied. <P />(3 data files).

---------------------------------------------------------
Title: A high-resolution study of episodic mass loss from the carbon
    star TT Cygni
Authors: Olofsson, H.; Bergman, P.; Lucas, R.; Eriksson, K.;
   Gustafsson, B.; Bieging, J. H.
2000A&A...353..583O    Altcode:
  CO radio line observations with the IRAM Plateau de Bure interferometer
  show that the carbon star TT Cyg is surrounded by a large (radius
  ~ 35arcsec or 2.7x10<SUP>17</SUP> cm), geometrically thin (average
  width ~ 2farcs 5 or 1.9x10<SUP>16</SUP> cm) shell of gas, which has a
  remarkable overall spherical symmetry (e.g., its radius varies by less
  than +/-3%). It expands with a velocity of ~ 12.6 km s<SUP>-1</SUP>. The
  emitting gas is very evenly distributed in the shell when averaged
  over a solid angle of about 0.2 steradians. We estimate a molecular
  hydrogen density of ~ 250 cm<SUP>-3</SUP>, a gas kinetic temperature
  of ~ 100 K, and a mass of ~ 0.007 M_sun for the shell if the medium
  is homogeneous. There is no evidence for matter immediately inside
  or outside the shell, nor is there any evidence for structure in the
  radial direction of the shell brightness distribution (it is essentialy
  perfectly fitted with Gaussians). The shell centre is displaced ~
  1farcs 7 (position angle ~ -20degr ) with respect to the star. We
  favour an interpretation of this displacement in terms of TT Cyg being
  a member of a binary system. We put forward several arguments for a
  shell medium that consists almost entirely of a large number of small
  (la 1arcsec ) clumps (in which case the density required to fit the
  observational data is much higher, ~ 10<SUP>4</SUP> cm<SUP>-3</SUP>,
  and the kinetic temperature is considerably lower, la 20 K). TT Cyg is
  presently losing mass at a modest rate, ~ 3x10<SUP>-8</SUP> M_sunpyr,
  and with a low expansion velocity, ~ 3.8 km s<SUP>-1</SUP>. This is
  inferred from CO line emission from a region centred on the present
  position of the star. The systemic velocity is estimated, from both
  the centre and the shell emission, to be -27.3+/-0.1 km s<SUP>-1</SUP>
  in the LSR system. All quantitative results are obtained assuming
  the Hipparcos distance of 510 pc. These data strongly support that TT
  Cyg has recently ( ~ 7x10<SUP>3</SUP> yr ago) gone through a period
  of drastically varying mass loss properties. We discuss briefly two
  scenarios: a short period (a few hundred years) of very intense mass
  loss (a rate in excess of 10<SUP>-5</SUP> M_sunpyr), and a related
  scenario with a more modest mass ejection and where most of the shell
  gas is swept-up from a previous, slower stellar wind. It is presently
  not possible to favour any of these two scenarios, but we suggest that
  in either case it is a coordinated mass ejection that caused the shell
  formation. The He-shell flash phenomenon in AGB-stars can provide this
  coordination, and it also fits the time scales involved.

---------------------------------------------------------
Title: Scattered Light from Envelopes around N-type Stars
Authors: Gustafsson, Bengt; Eriksson, Kjell; Kiselman, Dan; Olander,
   Nils; Olofsson, Hans; Schwarz, Hugo E.
2000IAUS..177..409G    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Abundances of light elements in metal-poor stars. II. Non-LTE
    abundance corrections
Authors: Gratton, R. G.; Carretta, E.; Eriksson, K.; Gustafsson, B.
1999A&A...350..955G    Altcode:
  We present non-LTE corrections to abundances of Fe, O, Na, and Mg
  derived from LTE analyses of F-K stars over a broad range of gravities
  and metal abundances; they were obtained using statistical equilibrium
  calculations and new model atoms. Line opacity was considered by
  means of an empirical procedure where it was attributed to a veil
  of weak Fe I lines; in the case of solar-type dwarfs, results were
  compared with those obtained using (LTE) mean intensities computed
  from OSMARCS models. We think that the empirical procedure produces
  better results for metal-poor stars, while mean intensities should
  perhaps be preferred for the Sun (where departures from LTE are
  anyway not very large). Collisions with both electrons and H I atoms
  were considered. Since cross sections for this second mechanism
  are very poorly known, we calibrated them empirically by matching
  observations of RR Lyrae variables at minimum light (discussed in
  Clementini et al. 1995). These stars were selected because non-LTE
  effects are expected to be larger in these stars than in those
  usually considered in the study of the chemical evolution of the
  Galaxy (cool main sequence and red giant branch stars). We found that
  different non-LTE mechanisms are important for the different species
  and transitions considered; on the whole, our calculations yielded
  moderate corrections to LTE abundances for high excitation O lines
  in warm dwarfs and giants, Na and Mg lines in giants and supergiants,
  and Fe I lines in F-supergiants (where corrections becomes very large
  for IR O lines). Non-LTE corrections were found to be negligible in
  the other cases studied. The Tables~1 to 12 are available only in
  electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr
  (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

---------------------------------------------------------
Title: Preliminary results on the circumstellar envelopes of alpha
    ORI and R Leo from CO 4.6 micron line emission
Authors: Ryde, N.; Gustafsson, B.; Hinkle, K. H.; Eriksson, K.;
   Lambert, D. L.; Olofsson, H.
1999A&A...347L..35R    Altcode:
  CO 4.6 mu m vibration-rotational lines are detected in fluorescent
  emission from the inner regions of the Betelgeuse (<ASTROBJ>alpha
  Orionis</ASTROBJ>) and <ASTROBJ>R Leonis</ASTROBJ> stellar winds. The
  spatially and spectrally resolved 1-0 R(1), R(2), and R(3) line profiles
  are found to be highly useful probes of circumstellar shells. The
  current data sample only a few regions of the circumstellar shells of
  the program stars. However, now it should be possible to obtain envelope
  maps and absolute flux estimates, allowing new independent estimates
  of mass loss rates. This will open up new possibilities in the study
  of the structure and dynamics of stellar winds around red giants. The
  temperature 4arcsec away from alpha Ori is found to be 38(+6}_{-5} {K)
  . For R Leo the temperature 4arcsec North is derived to be 24(+3}_{-2}
  {K) and 4arcsec South 35(+7}_{-4} {K) .

---------------------------------------------------------
Title: The nature of the circumstellar CO_2 emission from M giants
Authors: Ryde, N.; Eriksson, K.; Gustafsson, B.
1999A&A...341..579R    Altcode: 1998astro.ph.11330R
  The 13-16mu m region observed by the Infrared Space Observatory (ISO)
  of several ABG stars are discussed. We present and analyse spectra
  of seven M giants which show carbon dioxide features. To explain the
  features of the bands, we suggest they originate from two different
  circumstellar layers, one being a warm and high density layer close
  to the star, possibly making the 15mbox {\mum} band optically thick,
  and the other being a large, cold and optically thin layer extending
  far out in the wind. This could explain the difference in temperatures
  of the different bands found in the analysis of the spectra and the
  number of molecules needed for the emission. It is demonstrated that
  in spite of the bands probably not being formed in vibrational LTE,
  the temperatures can be estimated from the widths of the bands. Based
  on observations with ISO, an ESA project with instruments funded by
  ESA Member States (especially the PI countries: France, Germany, the
  Netherlands and the United Kingdom) and with the participation of ISAS
  and NASA. The SWS is a joint project of SRON and MPE.

---------------------------------------------------------
Title: A thin molecular shell around the carbon star TT CYG
Authors: Olofsson, H.; Bergman, P.; Lucas, R.; Eriksson, K.;
   Gustafsson, B.; Bieging, J. H.
1998A&A...330L...1O    Altcode:
  Interferometric CO({\jtra10} and {\tra21}) observations reveal a
  remarkably thin shell of molecular gas around the carbon star TT Cyg,
  width/radius la 1farcs 3/34arcsec ~ 0.04. It expands at ~13{km s(-1) ,
  and contains ~ 0.02M_sun of gas provided the CO abundance with respect
  to H_2 is 10(-3) and the distance is 1kpc. Only about a quarter of the
  shell has been mapped, but we infer an overall spherical shell with
  only small, but clear, deviations at the per cent level. The radial
  structure of the shell is barely resolved at the arc second level,
  but there exists weak emission extending a few arc seconds inwards
  from the peak. A drastic change in mass loss properties, possibly
  combined with the effects of interacting winds, provides the most
  likely explanation to the origin of the shell. %

---------------------------------------------------------
Title: Tentative Detection of Circumstellar CO2 from the AGB Star
    R Crateris
Authors: Ryde, N.; Eriksson, K.; Gustafsson, B.; Lindqvist, M.;
   Olofsson, H.
1998Ap&SS.255..301R    Altcode: 1997Ap&SS.255..301R
  We report on and discuss the detection of an emission feature at 14.98
  µm from the oxygen-rich, semi-regularly pulsating Asymptotic Giant
  Branch star R Crateris, a feature which we suggest to be due to the
  &lt;Stack&gt; <SUB>0</SUB> <SUP>1</SUP> &lt;/Stack&gt; Q-branch of
  circumstellar CO2. We also suggest a reasonable excitation mechanism,
  which could explain the height, the width and the asymmetry of the
  feature.

---------------------------------------------------------
Title: Modelling of molecular bands of oxygen-rich AGB stars
Authors: Ryde, N.; Eriksson, K.; Gustafsson, B.; Olofsson, H.; Plez, B.
1998IAUS..191P.118R    Altcode:
  ISO observations of infrared molecular bands of oxygen-rich AGB stars
  are compared with synthetic spectra generated using model atmospheres
  from the new large grid of model atmospheres that we are currently
  calculating with the newest MARCS code in spherical geometry. Seven
  molecular bands of eight M-giants, observed by ISO in medium resolution
  mode (SWS06), are analysed in this way.

---------------------------------------------------------
Title: Modelling of ISO-SWS spectra of red giants
Authors: Decin, L.; Cohen, M.; Eriksson, K.; Gustafsson, B.; Huygen,
   E.; Morris, P.; Plez, B.; Sauval, J.; Vandenbussche, B.; Waelkens, C.
1998IAUS..191P.120D    Altcode:
  The modelling and interpretation of the ISO-SWS (Infrared Space
  Observatory - Short Wavelength Spectrometer) data require accurately
  calibrated spectrometers. In the SWS spectral region (2.38-45.2 microns)
  the primary standard calibration candles are bright, mostly cool,
  stars. The better these calibration sources are known in the infrared,
  the more accurate the spectrometers can be calibrated. Since ISO offers
  the first opportunity to observe in the infrared with a resolving power
  of ~1500, our knowledge on stellar sources -and more specifically on
  stellar atmospheres- is not so refined. A full exploitation of the ISO
  data will therefore result from an iterative process in which both
  accurate observations and new modelling are involved. A comparison
  between the observed SWS spectra and the predicted ones based on the
  Opacity Sampling spherical models of B. Plez (Plez et al., 1992; 1993)
  is performed. This reveals not only calibration problems, but also
  shortcomings in generating the synthetic spectra. Our results will not
  only contribute to a better calibration of the ISO-SWS data, but also to
  a better understanding and modelling of the atmosphere of cool giants.

---------------------------------------------------------
Title: Mid and far-infrared spectra of the third brightest carbon
    star IRAS 15194-5115
Authors: Ryde, N.; Eriksson, K.; Gustafsson, B.; Jorgensen, U. G.;
   Nyman, L. -Aa.; Olofsson, H.; Plez, B.; Wolstencroft, R.
1998IAUS..191P.312R    Altcode:
  ISO observations from 2 to 197 microns of the recently discovered,
  third brightest (at 12 microns) carbon star IRAS 15194-5115, are
  analysed. Eighty spectra, covering the entire range from 2.3 microns
  to 45 microns, were observed in the ISO medium-high resolution mode
  (SWS06). Also, observations were made with the ISO long wavelength
  spectrometer (LWS) from 42 to 197 microns. The evolutionary stage and
  chemistry are discussed and a comparison to the similar carbon star
  IRC+10216 is made.

---------------------------------------------------------
Title: Episodic mass loss of the carbon star TT CYG
Authors: Olofsson, H.; Bergman, P.; Lucas, R.; Eriksson, K.;
   Gustafsson, B.; Bieging, J. H.
1998IAUS..191P.415O    Altcode:
  There exists now seven carbon stars for which there is good evidence
  that the mass loss has been highly episodic. Detached gas shells were
  first imaged in circumstellar CO emission, R Scl, U Ant, S Sct, and TT
  Cyg (see Olofsson et al. 1996), or in other molecular line emissions,
  U Cam. Detached dust shells have been observed towards U Hya, Y CVn, and
  U Ant (probably two shells). So far there is only one M-star for which a
  similar detached shell has been found, R Hya. It has been suggested that
  these shells are due to episodic high mass loss rate events connected
  with the thermal pulses of the central star. In this poster we present
  high resolution (~2 arcsecond) CO(J = 1-0) observations of the carbon
  star TT Cyg performed with the IRAM interferometer on Plateau de Bure,
  France (a minor part of the data have been presented in Olofsson et
  al. 1998). To cover the entire shell we have observed eight primary
  fields. We have used four configurations to be sensitive to extended
  as well as sharply peaked emission. The data reveal an overall close
  to spherically symmetric, very narrow (width/radius approximately less
  than 0.04, except to the north) shell. Yet, there are clear deviations
  from perfect spherical symmetry, e.g., the star does not lie exactly
  at the centre of the shell, which appears to break up in the north. The
  brightness distribution is very patchy. If the shell is due to a phase
  of substantially increased mass loss, the time scale for this phase is
  at most a few hundred years and the mass loss rate must have approached
  10^{-4} M<SUB>odot</SUB> yr^{-1} ~5000 years ago (adopting the HIPPARCOS
  distance of ~500 pc). The present mass loss of the star is very low.

---------------------------------------------------------
Title: Images in scattered light of detached circumstellar shells
Authors: Delgado, D. G.; Olofsson, H.; Schwarz, H.; Eriksson, K.;
   Gustafsson, B.
1998IAUS..191P.404D    Altcode:
  The temporal variations of the mass loss rate of an AGB-star as it
  evolves is to a large extent unknown. This applies to all time scales
  from the pulsation period to the full time scale for the AGB-phase. For
  the shortest time scales we are limited by the spatial resolution of
  the observations, while for the longest time scales we lack suitable
  observational probes. On the intermediate time scales (10^2-10^4
  yr) there is now growing evidence for substantial variations in the
  mass loss rate, perhaps due to the effects of thermal pulses. Some
  of the best examples are provided by CO radio line observations of
  detached gas shells, and at least in one case the shell is extremely
  narrow compared to its radius (width/radius approximately less than
  0.04, see P4-15). The interpretation of the CO data are hampered by
  the fact that the emission depends on the excitation as well as the
  photodissociation of the CO-molecules, and hence the relation between
  the density distribution (and consequently the mass loss history)
  and the brightness distribution is uncertain. Here we present images
  obtained in 50 AA narrow filters (centered on the KI and Na D lines)
  with the ESO 3.6m telescope of three carbon stars with detached CO
  shells: R Scl, U Ant, and S Sct. In the two former we detect light
  scattered in extended envelopes. The brightness is relatively constant
  out to a relatively sharp outer radius, R Scl (~19 arcsecond) and U
  Ant (~41 arcsecond). For U Ant this radius coincides exactly with the
  observed peak radius of the CO shell. For R Scl this radius coincides
  with the outer radius of the CO distribution (as estimated from a
  model fit to the CO data; the CO shell is only marginally resolved
  and hence its radius is not well determined). [In the case of S Sct,
  with the largest CO shell radius (~70 arcsecond), no scattered light
  is detected.] This strongly supports the conclusion that the density
  distribution has a sharp outer edge. The shell distribution of the CO
  emission can only be reasonably explained by a sharp inner edge of the
  density distribution. Hence, these stars have gone through a period of
  significant change in the mass loss rate. Whether the shells are formed
  by a brief period of very enhanced mass loss, or are due to a faster
  wind sweeping up material from a slower wind remains to be determined.

---------------------------------------------------------
Title: Hubble Space Telescope Spectroscopy of the Carbon Star
    TX Piscium
Authors: Carpenter, Kenneth G.; Robinson, Richard D.; Johnson, Hollis
   R.; Eriksson, Kjell; Gustafsson, Bengt; Pijpers, Frank P.; Querci,
   Francois; Querci, Monique
1997ApJ...486..457C    Altcode:
  Ultraviolet spectra obtained with the Hubble Space Telescope of the
  carbon star TX Piscium (HR 9004) are presented, along with analysis
  providing information on its outer atmosphere, including flow and
  turbulent velocities, line formation mechanisms, and variations with
  time. Both thermal (collisionally excited) and fluorescent emission
  from the chromosphere of the star appear to be formed near the stellar
  rest velocity, i.e., in a region below that in which the stellar wind is
  accelerated. Absorption self-reversals in the Mg II emission confirm the
  presence of an outflowing stellar wind at a mean velocity of about 9-10
  km s<SUP>-1</SUP>. Circumstellar absorption features (Mn I and Fe I)
  overlying the Mg II emission indicate a cool shell expanding at about
  5-6 km s<SUP>-1</SUP> relative to the photosphere. The widths (FWHM)
  of various emission lines indicate that the chromospheric turbulence is
  at least 16 km s<SUP>-1</SUP>, but that it may increase with altitude
  to as much as 34 km s<SUP>-1</SUP>. Three hours of integration on
  the C II] lines are examined for any signs of variability that might
  indicate the presence of shocks, but no statistically significant
  variations are seen. A previous identification (in spectra of UU Aur)
  of an emission line at 2807 Å, seen only in spectra of carbon stars,
  as belonging to Fe I multiplet UV45 pumped by the C II] line at 2325 Å
  is confirmed by the discovery of an absorption feature corresponding
  exactly to the wavelength of the pumped transition (Fe I UV13) near
  2325 Å. Lines from Fe II UV165, previously seen in solar off-limb
  spectra and in Goddard High-Resolution Spectrograph spectra of α Tau,
  are clearly present. The normally much stronger Fe II UV32, 62, and
  63 multiplets are seen but are weaker relative to both the UV165 lines
  and the intercombination lines of C II] and Si II] than in α Tau. The
  weakness of these Fe II lines is indicated both by their absolute flux
  levels and by their narrow, single-peaked profiles, which are in sharp
  contrast to the broad, double-peaked profiles seen in oxygen-rich cool
  giant and supergiant stars. The weakness of the Fe II lines and the
  presence of the Fe I 2807 Å line suggest that the ionization fraction
  of iron (Fe II/Fe I) is significantly lower in the outer atmospheres of
  carbon stars. Fluxes in emission lines of Fe II and Mg II are &gt;=2-3
  times lower than in a 1984 IUE spectrum of TX Psc, confirming that
  the latter was obtained at an epoch of unusual UV brightness for the
  star. The Mg II profiles are heavily mutilated by overlying absorption,
  even more so than in 1984. The TX Psc profiles are very similar to
  those seen in the carbon star TW Hor but are dramatically different
  than those in another carbon star, UU Aur, whose lines show violet
  wing emission out to much shorter wavelengths than in the other two
  stars. <P />Based on observations with the NASA/ESA Hubble Space
  Telescope, which is operated by the Association of Universities for
  Research in Astronomy, Inc., under NASA contract NAS 5-26555 and on
  observations at the Haute-Provence Observatory.

---------------------------------------------------------
Title: (Erratum) Line-blanketed model atmospheres for R Coronae
    Borealis stars and hydrogen-deficient carbon stars.
Authors: Asplund, M.; Gustafsson, B.; Kiselman, D.; Eriksson, K.
1997A&A...323..286A    Altcode:
  Erratum to Astron. Astrophys. 318, 521-534 (1997)

---------------------------------------------------------
Title: Molecules in Circumstellar Envelopes of Carbon Stars
Authors: Larsen, F.; Olofsson, H.; Eriksson, K.; Gustafsson, B.
1997Ap&SS.251..235L    Altcode:
  We have searched for line emission from various transitions of
  a number of molecules, including CO, HCN, CN, CS and SiO, as
  well as some of their isotopic variants, towards a sample of 68
  bright carbon stars. Part of the data has already been published
  in Olofsson et al. (1993a,b). The aim of the project is to obtain a
  better understanding of the carbon star phenomenon and the processes
  involved. In particular, we would like to obtain reliable mass loss
  rates and molecular abundances for these objects. This requires careful
  and detailed modelling, which is currently underway. Our hope is that
  the study of these bright carbon stars will serve as a guide to the
  study of higher mass loss rate objects. Some preliminary observational
  results are presented here.

---------------------------------------------------------
Title: KI emission from envelopes around N-type stars. Spectroscopic
    observations and interpretations.
Authors: Gustafsson, B.; Eriksson, K.; Kiselman, D.; Olander, N.;
   Olofsson, H.
1997A&A...318..535G    Altcode:
  Circumstellar envelopes around three bright N-type stars, R Scl,
  X TrA, and V Aql have been detected in emission in resonance lines
  from KI. This radiation, which is most probably scattered photospheric
  radiation, was first found spectroscopically, but has later been imaged
  with coronographic and polarimetric techniques. In the present paper,
  which is the first in a series, the spectroscopic KI observations are
  discussed. From the observations of the KI 769.9nm emission we find
  systemic and expansion velocities in fair agreement with those obtained
  from the CO millimetre lines. We find a decline of the emission with
  distance from the star, in rough agreement with the assumption of a
  constant expansion velocity, mass-loss rate and KI abundance. Our mass
  loss rate estimates from the KI line observations agree rather well with
  those obtained from CO (ranging from 1/4 to 1/1 of the CO mass loss),
  which suggests that a considerable fraction of the potassium stays
  neutral through the envelope. This puts strong upper limits on the
  photoionizing chromospheric UV emission from the stars. Some indirect
  indications that the envelopes have inhomogeneous structures, clumps,
  are discussed.

---------------------------------------------------------
Title: Line-blanketed model atmospheres for R Coronae Borealis stars
    and hydrogen-deficient carbon stars.
Authors: Asplund, M.; Gustafsson, B.; Kiselman, D.; Eriksson, K.
1997A&A...318..521A    Altcode:
  We have constructed line-blanketed model atmospheres for the
  hydrogen-deficient and carbon-rich R Coronae Borealis (RCrB) stars,
  as well as for the similar hydrogen-deficient carbon (HdC) stars and
  the cool extreme helium (EHe) stars. Improved continuum opacities have
  been used together with realistic line absorption data for atomic
  and molecular transitions. The observed dereddened fluxes of R CrB
  are compared with the calculated model fluxes and found to agree best
  with a model effective temperature of 6900K, while the infrared flux
  method gives between 6600 and 6900K, depending on the nature of the
  flux excess in the J and H bands compared to the model fluxes. The
  excess may correspond to a recently formed dust cloud close to the
  star, with a typical temperature around 2000K and a dust mass of
  ~10^-11^M<SUB>sun</SUB>_. The agreement for the ultraviolet flux
  distribution is also very satisfactory as seen from IUE spectra of
  RCrB. Theoretical broad band photometry is presented and effective
  temperatures of RCrB and HdC stars estimated. The constructed
  models show a significantly steeper temperature gradient compared
  to previously existing models as a result of the line opacity. Due
  to the cool surface and high abundance of carbon, molecular bands of
  e.g. C_2_ and CO are visible in the spectra even at as high effective
  temperatures as 7000K. Furthermore, the high temperatures encountered
  at depth explain the observed Hei and CII lines for T_eff_ down to
  ~7000K. In the inner layers (τ_Ross_ &gt; 3) the models show density
  inversions related to the ionization zone of helium. For certain low
  gravity models the luminosity exceeds the local Eddington limit and
  hence gas pressure inversions occur as well, which could be related
  to the decline events of RCrB stars.

---------------------------------------------------------
Title: The ISO-SWS flux standard stars: synthetic spectra and
    observations.
Authors: der Bliek, N. S.; Morris, P. W.; Vandenbussche, B.; Waters,
   L. B. F. M.; Zaal, P.; Bell, R. A.; Gustafsson, B.; Eriksson, K.;
   de Graauw, T.
1997IAUS..189...89D    Altcode: 1998IAUS..189...89D
  The authors present flux-calibrated, synthetic spectra for the
  calibration stars of the Short Wavelength Spectrometer of the Infrared
  Space Observatory ISO-SWS.

---------------------------------------------------------
Title: H band spectra of cool dwarfs and giants
Authors: van der Bliek, N. S.; Gustafsson, B.; Eriksson, K.
1997IAUS..189P..32V    Altcode: 1998IAUS..189P..32V
  No abstract at ADS

---------------------------------------------------------
Title: Accuracy of synthetic far IR fluxes of stars
Authors: van der Bliek, N. S.; Gustafsson, B.; Eriksson, K.
1997IAUS..189P..28V    Altcode: 1998IAUS..189P..28V
  No abstract at ADS

---------------------------------------------------------
Title: Comparison Bertween ISO-SWS Observations and Synthetic Spectra
    of K Giants and M Giants α Boo and β Peg (Invited Paper)
Authors: Decin, L.; Cohen, M.; Eriksson, K.; Gustafsson, B.; Huygen,
   E.; Morris, P.; Plez, B.; Sauval, J.; Vandenbussche, B.; Waelkens, C.
1997ESASP.419..185D    Altcode: 1997fiso.work..185D
  The accurate flux calibration of SWS requires the observation of spectra
  of stellar templates (Schaeidt et al., 1996). On the other hand, our
  knowledge of stellar spectra in the broad spectral domain that ISO has
  opened for the first time is still incomplete, and must be improved
  with these same ISO data. Clearly, the final flux calibration of SWS
  data will result from an iterative process, that should benefit to
  both our understanding of the instrument and of the atmo- spheres of
  cool stars. We report on the progress of a project which confronts SWS
  observations of cool stars with state-of-the-art synthetic spectra. The
  ISO observations enable us to discriminate between various sources of
  molecular data and put tight constraints on the atmospheric parameters
  of the stellar templates. Preliminary results suggest that a 2% relative
  flux accuracy may be attainable in bands 1 and 2 of the SWS range.

---------------------------------------------------------
Title: Carbon stars with episodic mass loss: observations and models
    of molecular emission from detached circumstellar shells.
Authors: Olofsson, H.; Bergman, P.; Eriksson, K.; Gustafsson, B.
1996A&A...311..587O    Altcode:
  We have obtained detailed CO radio line maps of the circumstellar
  medium around the bright carbon stars R Scl, U Ant, S Sct, and TT
  Cyg. They provide direct evidence for the existence of large [radii
  between 10-70", or (1-5)x10^17^cm], geometrically thin (we estimate
  that the shell widths are &lt;~10"), over-all spherically symmetric
  shells of CO line-emitting gas around these stars. The shells expand
  with velocities in the range 13-20km/s, i.e., their ages lie in
  the range (1-10)x10^3^years. Less extensive CO observations of
  the carbon star V644 Sco suggest that also it is surrounded by a
  detached shell. The expansion velocities of the present mass loss
  winds, as evidenced by weak CO emission from regions close to the
  stars, are considerably lower, of the order 5km/s. We conclude that
  the mass loss characteristics of these, otherwise apparently normal,
  carbon stars have changed significantly over the last 10^4^years. For
  such a shell structure, the most reasonable cause is a short period
  of very intense mass loss (i.e., a mass loss eruption), although
  an interacting-wind scenario cannot be excluded. The CO brightness
  distributions are very patchy, suggesting an inhomogeneous circumstellar
  medium. Using a model where the shell consists of a large number of
  small, homogeneous clumps, we estimate that the H_2_-masses of the
  four, spatially resolved shells are all around 0.01M<SUB>sun</SUB>_
  (for an adopted CO abundance with respect to H_2_ of =~10^-3^), and
  that in the mass loss eruption -scenario the H_2_-mass loss rates
  of the stars were =~10^-5^x(10"/{DELTA}R)M<SUB>sun</SUB>_/yr during
  the formation of the shells ({DELTA}R being the unresolved shell
  width in arc seconds). The present mass loss rates are very low,
  &lt;~10^-7^M<SUB>sun</SUB>_/yr. These results suggest that the four
  stars have all gone through a type of event that led to a dramatic
  change in the mass loss characteristics. The adopted model is an
  initial, relatively crude, attempt to provide a more realistic base
  for the interpretation of line emission from a circumstellar medium
  in which, in general, the physical conditions are very likely quite
  inhomogeneous. It is the accidental overlap along the line-of-sight
  and in velocity space of the many small clumps that in the model
  produces a clumpy appearance of the brightness distribution, at the
  larger scale set by the observational resolution, that resembles the
  observed ones. In the mass loss eruption -scenario the estimated life
  time of a CO line-emitting shell of the type discussed in this paper
  is =~10^4^years, and it is determined by the photodissociation of the
  CO molecules. Only shells younger than =~10^3^years are expected to
  be observable in molecular radio lines other than those of CO. There
  is a period after formation when such shells should be characterized
  by very anomalous line intensity ratios. For instance, in our model
  the line intensity ratio between the photodissociation product CN
  and the parent molecule HCN increases drastically on a time scale of
  hundreds of years as the shell recedes from the star. We suggest that
  the shell around R Scl is in this phase, since this is the only object,
  among the five observed, in which we have clearly detected also lines
  of HCN and CN, albeit with anomalous line intensity ratios.

---------------------------------------------------------
Title: Stellar far-IR fluxes: how accurate are model predictions?
Authors: van der Bliek, N. S.; Gustafsson, B.; Eriksson, K.
1996A&A...309..849V    Altcode:
  We present the results of an analysis of the accuracy of predicted
  far infrared (FIR) fluxes of stars. Sources of errors are a) the input
  parameters for the model atmospheres; b) assumptions in the modelling,
  resulting in errors in the structure of the model atmospheres; c) the
  adopted IR continuous opacity, dominated by the H^-^_ff_ opacity; d)
  the possible presence of circumstellar (CS) dust. Stellar effective
  temperatures are typically determined with an accuracy of about
  100K. This leads to an uncertainty in the predicted far infrared
  (FIR) flux of 1 to 4%, depending on the spectral type. Errors in the
  other two fundamental parameters of a star, the surface gravity and
  the metallicity, have a minor effect on the prediction of stellar FIR
  fluxes, less than 1%. The various assumptions made in the modelling
  result in errors in the temperature structure T(τ) of model
  atmospheres. By using the depth and shape of spectral lines, T(τ)
  in the outer layers of the atmosphere, where the lines are formed,
  can be pinned down to about 100K, resulting in uncertainties of about
  1 to 2% in the FIR. Errors in the H^-^_ff_ opacity are small and as a
  result uncertainties in the FIR fluxes due to the continuous opacity are
  less than 0.1%. CS dust can have a large impact on the IR fluxes. We
  find that the uncertainties due to the possible presence of CS dust
  can be more than an order of magnitude larger than the uncertainties
  resulting from modelling the stellar atmosphere. Unfortunately with
  the present day accuracies of IR data no further constraints can be
  set to limit these uncertainties.

---------------------------------------------------------
Title: Interferometric molecular line observations of the
    circumstellar envelope(s) around U Camelopardalis.
Authors: Lindqvist, M.; Lucas, R.; Olofsson, H.; Omont, A.; Eriksson,
   K.; Gustafsson, B.
1996A&A...305L..57L    Altcode:
  We have observed the circumstellar envelope of the carbon star U
  Cam in the HCN(J=1-&gt;0) and CN(N=1-&gt;0) lines using the IRAM
  Plateau de Bure interferometer. There is evidence of a two-envelope
  structure: an outer extended envelope, possibly a shell, with a radius
  of ~7x10^16^cm, that expands with a velocity of ~25km/s, surrounding an
  inner envelope with a radius of ~6x10^15^cm and an expansion velocity
  of only ~13km/s. Mass loss rate estimates based on these data alone
  are uncertain, but they suggest that the mass loss rate during the
  formation of the outer envelope was higher than during the present
  mass loss epoch. Thus, we have evidence for a significant variation
  in the mass loss characteristics of U Cam within the last 10^3^years.

---------------------------------------------------------
Title: Outer Layers of a Carbon Star: The View from the Hubble
    Space Telescope
Authors: Johnson, Hollis R.; Ensman, Lisa M.; Alexander, David R.;
   Avrett, Eugene H.; Brown, Alexander; Carpenter, Kenneth G.; Eriksson,
   Kjell; Gustafsson, Bengt; Jorgensen, Uffe G.; Judge, Philip D.; Linsky,
   Jeffrey L.; Luttermoser, Donald G.; Querci, Francois; Querci, Monique;
   Robinson, Richard D.; Wing, Robert F.
1995ApJ...443..281J    Altcode:
  To advance our understanding of the relationship between stellar
  chromospheres and mass loss, which is a common property of carbon stars
  and other asymptotic giant branch stars, we have obtained ultraviolet
  spectra of the nearby N-type carbon star UU Aur using the Hubble
  Space Telescope (HST). In this paper we describe the HST observations,
  identify spectral features in both absorption and emission, and attempt
  to infer the velocity field in the chromosphere, upper troposphere,
  and circumstellar envelope from spectral line shifts. A mechanism
  for producing fluoresced emission to explain a previously unobserved
  emission line is proposed. Some related ground-based observations are
  also described.

---------------------------------------------------------
Title: Early Proterozoic crustal evolution: Geochemical and NdPb
    isotopic evidence from metasedimentary rocks, southwestern North
    America
Authors: McLennan, S. M.; Hemming, S. R.; Taylor, S. R.; Eriksson,
   K. A.
1995GeCoA..59.1153M    Altcode:
  Early Proterozoic (1.8-1.7 Ga) metasedimentary rocks in northern New
  Mexico and southern Colorado, USA, can be divided into turbidite
  successions (commonly volcanogenic) associated with mafic/felsic
  metavolcanic successions (e.g., Irving Fm.) and stable shelf
  quartzite-pelite successions of shallow marine origin (e.g., Hondo
  Gp.). Metapelites from the turbidite successions reported here
  have low K<SUB>2</SUB>O/Na<SUB>2</SUB>O, low Th/U (&lt;3.0), low to
  moderate Th/Sc (0.1-0.6), and slight negative Eu-anomalies, although
  regionally, negative Eu-anomalies in such rocks are common. At the
  time of sedimentation (ca. 1.7-1.8 Ga), ɛ<SUB>Nd</SUB> values were
  in the range +3 to +7, indistinguishable from associated metavolcanic
  and plutonic rocks. Similarly, lead isotopic data scatter about a
  1.7 Ga reference isochron. Low κ (<SUP>232</SUP>Th/<SUP>238</SUP>U)
  values for the Irving Formation are consistent with derivation from
  crustal sources similar to the southern Colorado/northern New Mexico
  lead isotope crustal province. These data are further consistent with a
  volcanic arc related origin. In contrast, stable shelf metapelites have
  high K<SUB>2</SUB>O/Na<SUB>2</SUB>O, variable but commonly high Th/U
  (2.0-7.0), moderate to high Th/Sc (0.5-1.4), and substantial negative
  Eu-anomalies. Although compositions are rather variable, they are
  typical of post-Archean shales. Neodymium isotopes are surprisingly
  radiogenic with ɛ<SUB>Nd</SUB>(1.7 Ga) in the range -0.2 to +4. Lead
  isotopic data for the least radiogenic samples also are consistent with
  a dominantly juvenile source and on a <SUP>207</SUP>Pb/<SUP>204</SUP>Pb
  vs. <SUP>206</SUP>Pb/<SUP>204</SUP>Pb diagram, data scatter slightly
  above the 1.7 Ga reference isochron, suggesting minor components of
  significantly older material. Lead isotopic systematics suggest that
  a major component of the provenance was derived from the immediately
  associated metavolcanic-plutonic terranes, consistent with suggestions
  of a first-cycle origin, but with an Archean component. Isotopic
  data restrict the Archean component to about 10%, on average, and
  no more than 25% in any sample. This older crustal component may be
  derived either by direct erosion of Archean rocks, such as the Wyoming
  Province, or indirectly through assimilation into Early Proterozoic
  igneous rocks. Although the stable shelf sedimentary rocks are derived
  from a provenance with similar ages as the volcanogenic turbidites,
  the geochemical characteristics of the provenance are significantly
  different. Accordingly, these data are consistent with especially
  rapid and widespread crustal growth and evolution in southwestern North
  America during the period 1.9-1.7 Ga. Several samples from the Hondo
  Group and Uncompahgre Formation have REE patterns that are rotated
  to LREE depletion and perhaps HREE enrichment. The change in REEs
  correlate with Mo, U, and V abundances and Pb isotopic characteristics
  suggesting sedimentary processes similar to those operating in black
  shales affected these REE patterns. REE patterns and Th/U ratios of
  Early Proterozoic volcanogenic turbidites examined in this and other
  studies differ on average from turbidites found in Archean greenstone
  belts. Negative Eu-anomalies are common, HREE-depletion is seen but
  comparatively rare, and Th/U ratios are commonly below 3.0. Accordingly,
  these data are consistent with models suggesting that the upper crust
  had a different composition in the Archean.

---------------------------------------------------------
Title: Interferometric Observations of HCN and CN towards Carbon Stars
Authors: Lindqvist, M.; Lucas, R.; Olofsson, H.; Omont, A.; Eriksson,
   K.; Gustafsson, B.
1995Ap&SS.224..501L    Altcode:
  Using the IRAM interferometer we have observed four carbon stars (U
  Cam, CIT6, Y CVn, IRC+40540) in the HCN(J=1 → 0) and CN(N=1 → 0)
  lines. Here we present some results for CIT6 and U Cam.

---------------------------------------------------------
Title: Sedimentology of archean greenstone belts: Signatures of
    tectonic evolution
Authors: Eriksson, K. A.; Krapez, B.; Fralick, P. W.
1994ESRv...37....1E    Altcode:
  Stratigraphic styles in Archean greenstone belts are compared to
  those of modern and Phanerozoic depositional basins in order to
  test the conformity of tectonic style through time. Six lithological
  associations in greenstone belts are recognized: (1) mafic-ultramafic
  volcanic, (2) calc-alkaline volcanic, (3) bimodal volcanic, (4)
  quartz arenite-iron-formation or carbonate, (5) conglomerate-wacke
  and (6) conglomerate-arenite. Examples of the associations are
  described from the Kaapvaal, Superior and Zimbabwe Provinces and
  the Pilbara Block. Each association differs only slightly between
  the four regions, thereby emphasizing a common tectonostratigraphic
  theme. Sedimentary rocks are a minor component of the mafic-ultramafic
  volcanic association. They were deposited in two types of volcanic-basin
  environments: one similar to barred lagoons and bays around oceanic
  volcanic islands, and the other similar to sediment-starved platforms
  adjacent to coalesced volcanoes in inter-arc, intra-arc and back-are
  basins. In contrast, sedimentary rocks in the calc-alkaline volcanic
  association comprise thick wedges of epiclastic and volcaniclastic
  detritus deposited in elongate sedimentary basins, and thick wedges
  of pyroclastic and volcaniclastic detritus deposited adjacent to
  volcanic centers. Sedimentary facies were identical to those of
  forearc-trench and marine volcanoplutonic-arc settings. Chemogenic
  lithofacies in both volcanic associations were deposited in shallow to
  deep-marine waters, although shallow-water profiles were selectively
  preserved in some terrains. Sedimentary rocks of the bimodal volcanic
  association are thick wedges of siliciclastic and volcaniclastic
  deposits interbedded with subaerial to submarine erupted flows of
  komatiite, basalt, and rhyolite. Depositional environments ranged
  from braid-plain and braid-delta to coastal marine and submarine
  fan. Starved-basin deposits include banded iron-formation and
  sulfidic black shale. The association is identical to that of
  cratonic extensional basins in arc-continent and intracontinental
  rifts. Sedimentary rocks of the quartz arenite-iron-formation or
  carbonate association onlap weathered basement or bimodal-volcanic
  association rocks. Depositional environments were either transitional
  from fluvial to siliciclastic and carbonate marginal-marine to
  offshore pelagic-hemipelagic, or from inshore intrabasinal-clastic and
  volcaniclastic to offshore pelagic-hemipelagic. Siliciclastic deposits
  are supermature. Two tectonic sites are represented: those with
  siliciclastic facies represent continent-adjacent syn- to post-rift
  stable shelves and those dominated by banded iron-formation, with
  volcaniclastic deposits, represent arc-adjacent post-rift stable
  shelves. Sedimentary rocks of the conglomerate-wacke association
  are represented by thick wedges of siliciclastic or volcaniclastic
  sandstone, with minor volcanic components. These were deposited in
  braid-plain, braid-delta and submarine-fan environments within elongate
  sedimentary basins. Coastal-plain and pelagic basin facies are also
  present. Siliciclastic detritus was derived from syndepositional,
  magmatic and metasedimentary thrust-belts. Two stratigraphic styles
  are preserved: one that records a flysch-like stage of deep-
  to marginal-marine environments, and the other that records a
  molasse-like stage of marginal-marine to fluvial environments. The
  association is identical to that of compressional-foreland basins of
  arc-continent collisional and compressional-arc tectonic affinities. The
  conglomerate-arenite association is preserved in elongate structural
  basins that transgress crustal components and all other supracrustal
  units. It is dominated by thick wedges of siliciclastic sandstone,
  although bimodal volcanic and volcaniclastic rocks can also be
  present. Depositional environments ranged from talus and alluvial fan,
  and braid-plain to either lacustrine or coastal marine. Local basin
  margins often show lateral offsets from source terrains and vertically
  skewed facies patterns. Longitudinal facies geometries are typical. The
  association is similar to that of strike-slip collisional graben in
  hinterland tectonic-escape and terrane-accretion orogens. The examples
  show that, despite all the ramifications of secular geophysical,
  geothermal and geochemical global change, the stratigraphic style of
  sedimentary rocks in Archean greenstone belts can be matched with modern
  tectonic analogues, thereby emphasizing the conformity of stratigraphic
  style through time. The inseparable link between stratigraphic and
  tectonic styles implies that the tectonic style of greenstone belts
  was not temporally unique. Major differences exist with regards to
  the chemical composition of certain magmatic and sedimentary products,
  but these are compensated for by their constant stratigraphic function
  in terms of depositional processes, depositional environments and
  tectonic sites.

---------------------------------------------------------
Title: A Study of Circumstellar Envelopes around Bright Carbon
    Stars. I. Structure, Kinematics, and Mass-Loss Rate
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.; Carlstrom, U.
1993ApJS...87..267O    Altcode:
  Results are presented of a survey of circumstellar CO emission on a
  sample of bright carbon stars, which is relatively complete out to
  about 900 pc from the sun. A total of 68 detections were made. All
  objects within 600 pc of the sun were detected. It is suggested that the
  large majority of all carbon stars have circumstellar envelopes. The
  CO-emitting parts of these envelopes have angular sizes less than
  about 15 arcsec. The median gas expansion velocity is 12.5 km/s, and
  the expansion velocities for the majority of the objects fall in the
  range 9-15 km/s. The median mass-loss rate is 1.5 x 10 exp -7 solar
  mass/yr, and the mass loss rate for the majority of stars lies within
  the narrow range (0.8-2.5) x 10 exp -7 solar mass/yr. Circumstellar
  and photospheric HCN, CN, and CS abundances are estimated and compared
  for a sample for bright carbon stars. The chemistry in the envelope
  around R Scl is determined.

---------------------------------------------------------
Title: A Study of Circumstellar Envelopes around Bright Carbon
    Stars. II. Molecular Abundances
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.; Carlstroem, U.
1993ApJS...87..305O    Altcode:
  We have estimated and compared circumstellar and photospheric HCN, CN,
  and CS abundances for a sample of bright carbon stars. The circumstellar
  HCN and CS abundances roughly correlate with the photospheric ones,
  but the former appear to be systematically overestimated by a factor
  of 5-10. Although we cannot exclude the presence of a circumstellar
  chemistry that efficiently produces HCN and CS in the inner parts
  of these relatively hot circumstellar envelopes, we attribute this
  difference between photospheric and circumstellar abundances to
  errors in the circumstellar envelope model used. In particular,
  for the low mass-loss rate objects a systematic underestimate of
  the mass-loss rate may be suspected. In addition to this general
  trend, stars that are in some sense peculiar also show circumstellar
  abundances that deviate significantly from the expected. There is
  evidence for the presence of maser features in the HCN (J = 1-0)
  emission toward some of the stars. The estimated circumstellar CN
  abundances suggest that this species is a photodissociation product of
  HCN. A search for circumstellar HNC, SiS, and HC<SUB>3</SUB>N shows
  that molecular emission from species other than CO, HCN, CN, and CS
  is very weak in these low mass-loss rate objects. An attempt has been
  made to determine the chemistry in the (probably detached) envelope
  around R Scl. The data suggest a carbon-rich chemistry. Finally, it
  is shown that the circumstellar <SUP>12</SUP>CO/<SUP>13</SUP>CO and
  H<SUP>12</SUP>CN/H<SUP>13</SUP>CN intensity ratios roughly correlate
  with the photospheric <SUP>12</SUP>C/<SUP>13</SUP>C isotope ratios
  for a small number of low mass-loss rate objects, although the former
  ratios are systematically lower than the latter by a factor of about 2.

---------------------------------------------------------
Title: Detailed modelling of the shell around S Scuti.
Authors: Eriksson, K.; Stenholm, L.
1993A&A...271..508E    Altcode:
  We have calculated a large number of models of the circumstellar
  material around the carbon star S Sct and compared the results with
  detailed maps in the CO J=1-O and J=2-1 lines. The radiative transfer
  calculations were performed in non-LTE using a nine-level CO model
  atom and using the geometrical assumption of spherical symmetry. The
  best fit to the main part of the emission was obtained for a thin
  shell far from the star.

---------------------------------------------------------
Title: A Complete Sample of Carbon Stars
Authors: Eriksson, K.
1993iue..prop.4732E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Geochemistry of 1.8-1.67 Ga mudstones and siltstones from
the Mount Isa Inlier, Queensland Australia: Provenance and tectonic
    implications
Authors: Eriksson, K. A.; Taylor, S. R.; Korsch, R. J.
1992GeCoA..56..899E    Altcode:
  Sedimentary and volcanic rocks overlying basement in the Mount Isa
  Inlier, Australia, are subdivided into three cover sequences. The upper
  two sequences range in age from 1800 to 1670 Ma and each consist of rift
  and overlying sag phases of sedimentation. Fine-grained siliciclastic
  sedimentary rocks in the upper two sequences define two distinct
  geochemical groups. Samples from Groups I and II are mainly from the
  lower and upper rift and upper thermal phases, respectively. One sample
  from the lower rift phase has affinities with Group II, whereas samples
  from the lower thermal phase belong to both Groups I and II. Eu/Eu∗
  values are 0.70 to 0.85 for Group Iand 0.55 to 0.70 for Group II. Group
  I samples are characterized by lower La/Sc and Th/Sc ratios and higher
  Cr/Th ratios than Group II. Cr, Niand Co concentrations are greater
  in Group I than Group II. Groups I and II also are distinguished on
  plots of Eu/Eu∗ vs. La <SUB>N</SUB>/Sm <SUB>N</SUB> and Eu/Eu∗
  vs. Gd <SUB>N</SUB>/Yb <SUB>N</SUB>. Two samples from Group I have
  elevated LREE/HREE and La <SUB>N</SUB>/Yb <SUB>N</SUB> ratios that are
  attributed to intense weathering as revealed by their high Chemical
  Index of Weathering values. The geochemical data reflect a combination
  of local and more distant regional provenances and can be related to
  the tectonic evolution of the Mount Isa Inlier. Group I samples are
  attributed to dilution of a mature, post-Archean source by addition of
  recycled mafic volcanics. Group II samples are typical post-Archean
  sediments derived from differentiated upper continental crust with
  no dilution by local sources. The lower rift phase displays great
  geochemical variability (samples from both groups) that is typical of
  active tectonic settings such as rifts. The great variability of samples
  from the lower sag phase (both groups) is surprising but probably
  reflects the diverse rock types beneath this basin. Stable tectonic
  conditions during this phase of sedimentation are indicated instead by
  major element geochemistry that records severe weathering. Similarity
  of the upper rift phase sample with some samples from the lower sag
  phase reflects recycling of the latter. Samples from the upper sag
  phase are remarkably uniform in composition (Group II) and reflect
  the stable tectonic conditions under which this basin developed.

---------------------------------------------------------
Title: The large-scale atmospheric motion field of Alpha Orionis
Authors: de Jager, C.; Eriksson, K.
1992iesh.conf..117D    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The circumstellar envelope of the carbon star S Scuti.
Authors: Olofsson, H.; Carlstrom, U.; Eriksson, K.; Gustafsson, B.
1992A&A...253L..17O    Altcode:
  CO(J = 1-0) observations of the bright carbon star S Sct show that
  the star is surrounded by a large (about 5.3 x 10 exp 17 cm) shell
  of gas expanding at a velocity of 16.5 km/s. It was produced during a
  brief period (about 1200 years) of high mass loss (about 4 x 10 exp-5
  solar mass/yr) about 10 exp 4 years ago. The current mass losss rate
  and gas expansion velocity are only about 3 x 10 exp -8 solar mass/yr
  and about 5 km/s, respectively. This indicates that the star has gone
  through a very eruptive phase, possibly induced by a thermal pulse. The
  simple kinematics of the shell makes it possible to infer an overall
  spherical symmetry of the otherwise definitely clumpy CO brightness
  distribution. Thus, the mass loss must have been globally spherically
  symmetric, and the material was probably ejected in the form of lumps.

---------------------------------------------------------
Title: S Persei : optical and water maser variability - 1984 to 1990.
Authors: Little-Marenin, I. R.; Benson, P. J.; McConahay, M. M.;
   Cadmus, R. R., Jr.; Stencel, R. E.; Eriksson, K.
1991A&A...249..465L    Altcode:
  The M supergiant S Persei was monitored since 1984 optically and
  since 1987 for water maser emission at 22 GHz. The dozen H2O maser
  features show complex variations in intensity with many of the features
  varying independently of one another. Some of the water maser features
  brightened dramatically at the time of the bright optical maximum
  observed in 1988 August and again 10 weeks later. It is possible the
  increase in water maser intensity is related to the ejection of a dust
  shell near the time of the preceding optical minimum. The intensity
  variations of the maser spectrum as being produced by an asymmetric
  distribution of maser spots are interpreted. A double shell of maser
  spots may be present on the near side of the shell, but appears to be
  lacking or be occulted on the far side. No chromospheric activity was
  detected about 10 weeks after optical maximum. A well developed shock
  is seen in a near-infrared spectrum obtained in 1988 October.

---------------------------------------------------------
Title: A comparison of photospheric and circumstellar HCN / CO
    -ratios for bright carbon stars.
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.
1990A&A...230..405O    Altcode:
  Measures of circumstellar HCN/CO abundance ratios for carbon stars are
  compared with corresponding ratios estimated from photospheric abundance
  analysis. A satisfactory agreement is found for most stars. However, V
  Hya and two 60 μm-excess sources have significantly lower circumstellar
  ratios than expected, and for the <SUP>13</SUP>C-rich stars the ratios
  are somewhat higher.

---------------------------------------------------------
Title: Bright carbon stars with detached circumstellar envelopes -
    A naturalconsequence of helium shell flashes ?
Authors: Olofsson, H.; Carlstrom, U.; Eriksson, K.; Gustafsson, B.;
   Willson, L. A.
1990A&A...230L..13O    Altcode:
  CO radio map data are presented for the bright carbon stars R Scl, U
  Ant, S Sct, and TT Cyg. The stars are found to have large circumstellar
  envelopes which, at least in the last three cases, are geometrically
  thin and clearly detached from the stars, indicating that the mass
  loss has occurred episodically. The possibility that these episodes
  are triggered by helium shell flashes is discussed and found consistent
  with existing data.

---------------------------------------------------------
Title: Book Review: Cool stars, stellar systems and the sun. /
    Springer-Verlag, 1987
Authors: Eriksson, K.
1990SSRv...52..195E    Altcode: 1990SSRv...52..195L
  No abstract at ADS

---------------------------------------------------------
Title: Modeling of shells around carbon stars.
Authors: Carlström, U.; Eriksson, K.; Gustafsson, B.; Olofsson, H.;
   Stenholm, L.; Willson, L. A.
1990apsu.conf...13C    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A Study of Bright Carbon Stars
Authors: Olofsson, H.; Carlstrom, U.; Eriksson, K.; Gustafsson, B.;
   Willson, L. A.
1990fmpn.coll..341O    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Chromospheres of Naked Carbon Stars
Authors: Eriksson, K.
1990iue..prop.3878E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: Observations of envelopes around carbon stars.
Authors: Eriksson, K.; Gustafsson, B.; Selhammar, M.
1990apsu.conf...26E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A comparison of photospheric and circumstellar
    (HCN)/(CO)-ratios for bright carbon stars
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.
1989STIN...9022477O    Altcode:
  Measures of circumstellar HCN/CO abundance ratios for carbon stars are
  compared with corresponding ratios estimated from photospheric abundance
  analysis. A satisfactory agreement is found for most stars. However,
  V Hya and two 60 micrometer-excess sources have significantly lower
  circumstellar ratios than expected, and for the (13)C-rich stars the
  ratios are somewhat higher.

---------------------------------------------------------
Title: SEST CO (J=1-0) observations of carbon-rich circumstellar
    envelopes.
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.
1988A&A...196L...1O    Altcode:
  The authors have used the Swedish ESO Submillimetre Telescope (SEST)
  to search for circumstellar CO (J = 1-0) emission towards bright carbon
  stars in the southern hemisphere. A correlation between the estimated
  mass loss rate and a far-IR excess measure is discussed. The CO (1-0)
  line profiles indicate a diversity in the characteristics of the
  circumstellar envelopes. In particular, two stars with distinctly
  double-peaked line shapes have been detected. One of them, S Sct,
  is interpreted in terms of an extended, cold, detached shell, with no
  hot gas/dust close to the star.

---------------------------------------------------------
Title: Accurate wavelengths in O II.
Authors: Eriksson, K. B. S.
1987JOSAB...4.1369E    Altcode: 1987OSAJB...4.1369E
  The wavelengths of 71 strong O II lines between 4676 and 525 Å have
  been measured. Improved energy levels have been derived. Smoothed
  wavelengths have been recalculated from these. The uncertainty is
  about 1 mÅ.

---------------------------------------------------------
Title: CO (J=1-0) observations of bright carbon stars.
Authors: Olofsson, H.; Eriksson, K.; Gustafsson, B.
1987A&A...183L..13O    Altcode:
  The authors have surveyed a sample of bright N-type stars, with recent
  estimates of chemical composition, in the CO(J = 1-0) line. Almost
  all stars were detected. The mass loss rate is well correlated with
  a far-IR excess measure, and the gas-to-dust mass ratio, estimated to
  be 350±200, seems relatively constant for this sample of stars. The
  mass loss rate appears to be dependent on the effective temperature,
  the carbon excess, and the <SUP>12</SUP>C/<SUP>13</SUP>C-ratio of the
  central star. In particular, the peculiar <SUP>13</SUP>C-rich stars have
  comparatively low mass loss rates. A weak dependence of gas expansion
  velocity of the circumstellar envelope on the carbon excess may exist.

---------------------------------------------------------
Title: Oxygen Isotopic Abundances in Evolved Stars. III. 26 Carbon
    Stars
Authors: Harris, Michael J.; Lambert, David L.; Hinkle, Kenneth H.;
   Gustafsson, Bengt; Eriksson, Kjell
1987ApJ...316..294H    Altcode:
  Oxygen isotope ratios have been measured in 21 ordinary N-type carbon
  stars and in five <SUP>13</SUP>C-rich J-type stars. The ratios in
  the ordinary N-type stars are 550 ≤ <SUP>16</SUP>O/<SUP>17</SUP>O
  ≤ 4100 and 700 ≤ <SUP>16</SUP>O/<SUP>18</SUP>O ≤ 2400. These
  ratios are much higher than expected and are extremely difficult to
  explain in terms of present theories of stellar evolution. The J-type
  stars exhibit ratios 350 ≤ <SUP>16</SUP>O/<SUP>17</SUP>O ≤ 850,
  <SUP>16</SUP>O/<SUP>18</SUP>O ratios being very uncertain. Together with
  nitrogen abundances measured by Lambert et al., these ratios preclude
  the envelope burning (hot-bottom convection) hypothesis which has been
  proposed for these stars.

---------------------------------------------------------
Title: Chemical composition and circumstellar shells of carbon stars -
    any obvious relations?
Authors: Eriksson, K.; Gustafsson, B.; Olofsson, H.
1987IAUS..122..381E    Altcode:
  The authors detectd CO emission from 8 of 12 bright, galactic N-type
  stars with different chemical profiles.

---------------------------------------------------------
Title: Line blanketing in model atmospheres of carbon stars.
Authors: Ekberg, U.; Eriksson, K.; Gustafsson, B.
1986A&A...167..304E    Altcode:
  A comparison of opacity sampling (OS) and opacity distribution function
  (ODF) methods for the calculation of the model atmospheres of carbon
  stars is presented. In order to determine the structure of OS model
  atmospheres to an accuracy of about 30 K or better, at least 5000
  frequency points with a near optimum distribution are found to be
  necessary. The ODF approximation is shown to cause significant errors,
  particularly where polyatomic opacity dominates in the surface layers,
  and the diatomic molecules at larger depths. The noncorrelation
  assumption is not found to lead to significant errors, even for very
  cool and carbon rich stars. Good agreement is found between multiple
  component ODF models and ODF models calculated using the ODF-summation
  procedure of Saxner and Gustafsson (1984) for single component ODFs.

---------------------------------------------------------
Title: The Chemical Composition of Carbon Stars. I. Carbon, Nitrogen,
    and Oxygen in 30 Cool Carbon Stars in the Galactic Disk
Authors: Lambert, David L.; Gustafsson, Bengt; Eriksson, Kjell;
   Hinkle, Kenneth H.
1986ApJS...62..373L    Altcode:
  Chemical compositions of 30 Galactic carbon stars are determined from
  high-resolution infrared spectra and new model atmospheres. Elemental C,
  N, and O abundances are quite similar to those seen in planetary nebulae
  and are consistent with those reported for G to M giants. Carbon stars
  show only modest carbon enrichments: C/O is less than 1.6, and half the
  sample have C/O less than 1.1. The <SUP>12</SUP>C/<SUP>13</SUP>C ratio
  is between 20 and 90 except for a few <SUP>13</SUP>C-rich stars. When
  line blanketing by HCN and C<SUB>2</SUB>H<SUB>2</SUB> is included,
  models predict the observed intensity of the H<SUB>2</SUB> quadrupole
  lines. This and other evidence shows that the carbon stars are not
  hydrogen-deficient.

---------------------------------------------------------
Title: Tz-Fornacis - an Eclipsing Capella-Like System Observed
    with IUE
Authors: Eriksson, K.; Saxner, M.; Gustafsson, B.; Ayres, T. R.;
   Linsky, J. L.; Anderson, J.
1986ESASP.263..225E    Altcode: 1986niia.conf..225E; 1986NIA86......225E
  The IUE observed TZ Fornacis at orbital phases 0.0, 0.25 and 0.79 in
  1986. Most of the exposures were LWP-HI or SWP-LO. Results show that:
  the surface fluxes for transition region emission lines are similar
  to those for the Capella system while that of the Mg II emission is
  smaller; the total flux in the Mg II emission lines is constant with
  phase, whereas the flux in the C IV emission lines decreases by 1/3
  during primary eclipse, indicating that most of the activity is due
  to the hotter giant (F7 III), which is also the case for Capella.

---------------------------------------------------------
Title: The outer atmosphere of the carbon star TX Piscium.
Authors: Eriksson, K.; Gustafsson, B.; Johnson, H. R.; Querci, F.;
   Querci, M.; Baumert, J. H.; Carlsson, M.; Olofsson, H.
1986A&A...161..305E    Altcode:
  A high-resolution LWP IUE spectrum of the bright N-type carbon star TX
  Psc demonstrates that the Mg II h and k emission profiles are strongly
  affected by absorption from Mg II, Mn I, probably Fe I, and possibly
  from molecules. The indication that the absorbing matter has a column
  density of not less than 10 to the 20th H atoms or molecules per sq
  cm is consistent with absorption in a slowly expanding envelope. The
  integrated Mg II line flux is found to be much greater than in 1981,
  and the radio CO (J = 1 - 0) line from the circumstellar shell is
  detected. Results for a column density of not larger than 10 to the 22nd
  H2 molecules/sq cm, and a radial velocity close to that of the star,
  are in agreement with those obtained from UV data. Some dust emission
  from carbon grains is suggested by the far infrared flux distribution,
  and a mass-loss rate estimation for the star of 10 to the -6th to 10
  to the -8th solar masses is obtained.

---------------------------------------------------------
Title: Carbon and oxygen abundances of field RR Lyrae
    stars. II. Oxygen abundances.
Authors: Butler, D.; Laird, J. B.; Eriksson, K.; Manduca, A.
1986AJ.....91..570B    Altcode:
  From non-LTE analysis of the neutral oxygen triplet (7771-7775 Å)
  absorption-line strengths on KPNO 4 m echelle plates, we have determined
  oxygen abundances and oxygen-to-iron ratios for a large number of field
  RR Lyrae stars covering the range in iron abundance +0.1&gt; [Fe/H]&gt;
  - 2.2. We have found that (1) RR Lyrae stars at the metal-poor end of
  the range have [O/Fe] values near zero. This is somewhat surprising
  since previous studies of metal-poor field stars have found oxygen
  to be enhanced relative to iron. (2) RR Lyrae stars at the metal-rich
  end of the range have [O/Fe] values between + 0.25 and + 0.95. Again,
  this result is in disagreement with expectations based on studies of
  other field stars in the disk. (3) The abundance sum C + N + O, or its
  possible range, has been determined. For most stars, including those
  at the metal-rich end of the range, the ratio (C + N + O)/Fe is high
  relative to the solar value. Possible explanations for these results
  are discussed.

---------------------------------------------------------
Title: The Unique Eclipsing Binary System TZ Fornacis
Authors: Eriksson, K.
1986iue..prop.2697E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: CNO abundances and <SUP>12</SUP>C/<SUP>13</SUP>C ratios in
    30 galactic N stars.
Authors: Gustafsson, B.; Lambert, D. L.; Hinkle, K. H.; Eriksson, K.
1985ESOC...21..151G    Altcode: 1985pdce.work..151G; 1985pdcn.conf..151G
  CNO abundances and C-12/C-13 ratios have been determined for 30 bright
  galactic N stars by means of high-resolution FTS spectra, obtained with
  the Kitt Peak 4 m Mayall reflector and covering the spectral region
  from 4000/cm to 6600/cm. The spectra were analyzed with a new grid of
  model atmospheres. Weak second-overtone vibration-rotation lines of CO
  were used for determining the oxygen abundances, while C2 lines of the
  Phillips system were used in the carbon determinations. Lines of the
  Ballik-Ramsay system give similar results. The nitrogen abundances
  were obtained from weak CN lines of the red system, and such lines
  were also used for the determination of C-12/C-13 ratios. Consistent
  isotopic ratios were obtained from the C-13O lines.

---------------------------------------------------------
Title: The temperatures of G and K stars.
Authors: Wing, R. F.; Gustafsson, B.; Eriksson, K.
1985IAUS..111..571W    Altcode:
  Effective temperatures have been determined for G and K stars by
  comparing synthetic colors computed from model atmospheres to observed
  colors measured at near-infrared continuum points. Results are presented
  for giant stars in the range K0 III - K4 III.

---------------------------------------------------------
Title: The Unique Eclipsing Binary System TZ Fornacis
Authors: Eriksson, K.
1985iue..prop.2278E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The outer atmosphere of the carbon star TX Piscium.
Authors: Eriksson, K.; Gustafsson, B.; Johnson, H. R.; Querci, F.;
   Querci, M.; Baumert, J. H.; Carlsson, M.; Olofsson, H.
1985BETSP...2....5E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A progress report on the analysis of long exposure SWP high
    resolution spectra of cool stars.
Authors: Linsky, J. L.; Ayres, T. R.; Brown, A.; Carpenter, K.;
   Jordan, C.; Judge, P.; Gustafsson, B.; Eriksson, K.; Saxner, M.;
   Engvold, O.; Jensen, E.; Moe, O. K.; Simon, T.
1984NASCP2349..445L    Altcode: 1984fiue.rept..445L; 1984IUE84......445L
  The IUE is the first experiment with sufficient sensitivity to obtain
  high resolution spectra (lambda/delta lambda is approximately 10,000)
  of many cool stars in the vitally important 1200 to 2000 A spectral
  region. These data provide qualitatively new information with
  which to understand the properties of and structures in the outer
  atmospheres of these stars. Also, these cool star spectra will be
  extremely useful in planning for the Space Telescope High Resolution
  Spectrograph, which will be 1000 times more sensitive than IUE but will
  be hampered by limited observing time and limited spectral bandwidth
  in each exposure. Very long exposure, high disperson SWP spectra of
  many stars located throughout the cool half of the HR diagram were
  obtained. These 12 to 21 hour exposures were obtained by combining
  NASA and Vilspa shifts so as to obtain the longest possible exposures
  at times of low background. Included are dwarf stars of spectral type
  G0 V to M2 V, G9.5 III to M5 II giants, G2 Ib to M2 Iab supergiants,
  a number of RS CVn-type systems, and Barium stars.

---------------------------------------------------------
Title: Effects of HCN molecules in carbon star atmospheres.
Authors: Eriksson, K.; Gustafsson, B.; Jorgensen, U. G.; Nordlund, A.
1984A&A...132...37E    Altcode:
  Existing model atmospheres for carbon stars as well as observations
  indicate that some polyatomic molecules may be important opacity
  sources in at least the cooler carbon stars. In order to investigate
  the importance of the absorption from HCN, which seems to be one
  of the most important polyatomic opacity sources, monochromatic
  absorption cross sections have been calculated at a great number of
  wavelengths for this molecule. These calculations have been based on
  the assumption that the ratios between the transition probabilities
  of the combination transitions relative to the fundamentals follow
  rules, deduced empirically for other molecules. Opacity distribution
  functions were calculated and model atmospheres including the HCN
  opacity were constructed. The effects of HCN on the models turned out
  to be remarkably great.

---------------------------------------------------------
Title: A model for the cosmic creation of nuclear energy-a
    reassessment
Authors: Eriksson, K. -E.; Islam, S.; Skagerstam, B. -S.
1984Natur.308..210E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: HCN and C2H2 in Carbon Stars
Authors: Eriksson, K.; Gustafsson, B.; Jorgensen, U. G.; Nordlund, A.
1984IAUS..105..199E    Altcode:
  HCN and C<SUB>2</SUB>H<SUB>2</SUB> have numerous bands at wavelengths
  where a major part of the stellar flux is transported. This opacity
  could therefore be of great importance when constructing models
  for cool carbon star atmospheres, but has not been included in
  earlier models. Models without the HCN and C<SUB>2</SUB>H<SUB>2</SUB>
  opacity show a strange transition to "thin", high-pressure atmospheric
  structures when T<SUB>eff</SUB> is decreased below about 2900K. When
  HCN (and C<SUB>2</SUB>H<SUB>2</SUB>) opacity was added in the model
  atmosphere calculations, great effects on the structure were found
  for the lower temperatures.

---------------------------------------------------------
Title: Outer atmospheres of cool stars. XIV. A model for the
    chromosphere and transition region of beta Ceti (G9.5 III).
Authors: Eriksson, K.; Linsky, J. L.; Simon, T.
1983ApJ...272..665E    Altcode:
  In the present chromospheric and transition region model for Beta
  Ceti, which is consistent with IUE spectra of the Mg II, C II,
  and C IV resonance lines, the Mg II h and k lines are treated
  in partial redistribution and the C II and C IV lines in complete
  redistribution. Computed line fluxes are presented for a range of models
  to show the range of permitted temperature structures. A comparison
  of the Beta Ceti model to models previously computed in a similar way
  for other stars shows a trend of decreasing chromospheric pressures
  and increasing geometric scales as single stars evolve across the
  transition region boundary. The present analysis also suggests that
  transition region pressures drastically decrease and geometric scales
  rapidly increase as single giant stars evolve to the right, toward
  the boudnary. Beta Ceti's exceptional X-ray brightness is discussed.

---------------------------------------------------------
Title: The Temperatures of G and K Stars
Authors: Wing, R. F.; Gustafsson, B.; Eriksson, K.
1983BAAS...15..969W    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The narrow ultraviolet emission lines of the red dwarf AU
    Microscopii(dM1.6e).
Authors: Ayres, T. R.; Eriksson, K.; Linsky, J. L.; Stencel, R. E.
1983ApJ...270L..17A    Altcode:
  It is pointed out that the red dwarfs are the smallest, coolest,
  faintest, least massive, but most common of normal main-sequence
  stars. The dMe (H-alpha emission) subclass of the red dwarfs
  exhibits the largest median soft X-ray to bolometric luminosity
  ratio of any group of late-type stars. In connection with the present
  investigation, attention is given to the first high-dispersion spectra
  of the chromospheric (6000 K) and higher temperature (up to 100,000
  K) emissions of a dMe star, AU Microscopii in the far-ultraviolet
  (1150-2000 A) and middle-ultraviolet (2000-3000 A) bands accessible to
  the International Ultraviolet Explorer (IUE). AU Mic is one of the most
  luminous of lower main-sequence stars in C IV and soft X-ray emission.

---------------------------------------------------------
Title: Geochemistry of Archean shales from the Pilbara Supergroup,
    Western Australia
Authors: McLennan, Scott M.; Taylor, S. R.; Eriksson, K. A.
1983GeCoA..47.1211M    Altcode:
  Archean clastic sedimentary rocks are well exposed in the Pilbara
  Block of Western Australia. Shales from turbidites in the Gorge
  Creek Group ( ca. 3.4 Ae) and shales from the Whim Creek Group
  ( ca. 2.7 Ae) have been examined. The Gorge Creek Group samples,
  characterized by muscovite-quartzchlorite mineralogy, are enriched in
  incompatible elements (K, Th, U, LREE) by factors of about two, when
  compared to younger Archean shales from the Yilgarn Block. Alkali
  and alkaline earth elements are depleted in a systematic fashion,
  according to size, when compared with an estimate of Archean upper
  crust abundances. This depletion is less notable in the Whim Creek
  Group. Such a pattern indicates the source of these rocks underwent
  a rather severe episode of weathering. The Gorge Creek Group also
  has fairly high B content (85 ± 29 ppm) which may indicate normal
  marine conditions during deposition. Rare earth element (REE) patterns
  for the Pilbara samples are characterized by light REE enrichment (
  La <SUB>N</SUB>/Yb <SUB>N</SUB> ≥ 7.5 ) and no or very slight Eu
  depletion ( Eu/Eu <SUP>∗</SUP> = 0.82 - 0.99 ). A source comprised
  of about 80% felsic igneous rocks without large negative Eu-anomalies
  (felsic volcanics, tonalites, trondhjemites) and 20% mafic-ultramafic
  volcanics is indicated by the trace element data. Very high abundances
  of Cr and Ni cannot be explained by any reasonable provenance model
  and a secondary enrichment process is called for.

---------------------------------------------------------
Title: Stellar atmospheres projects.
Authors: Eriksson, K.
1983ITABO..60...37E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The Narrow Ultraviolet Emission Lines of the Red Dwarf AU
    Microscopii (dM1.6e)
Authors: Ayres, T. R.; Eriksson, K.; Gustafsson, B.; Linsky, J. L.;
   Saxner, M.; Stencel, R. E.
1982BAAS...14Q.865A    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A model for the cosmic creation of nuclear exergy
Authors: Eriksson, K. -E.; Islam, S.; Skagerstam, B. -S.
1982Natur.296..540E    Altcode:
  The exergy<SUP>1</SUP> of a physical system is the maximum amount of
  mechanical work that can be extracted from that system so that a system
  in thermodynamic equilibrium has zero exergy. An old theme in cosmic
  thermodynamics is that the second law implies that the Universe is
  running down (running out of exergy) and approaching thermodynamic
  equilibrium, `heat death'. However, in the standard model of the
  early Universe<SUP>2</SUP>, at 0.01 s after the big bang the Universe
  consisted of ordinary matter (nucleons), electrons and positrons,
  neutrinos, photons and gravitons. The gravitons were decoupled, but the
  others were in thermodyamic equilibrium. Thus the Universe had already
  reached the state of heat death, and its exergy was zero. The main
  problem is, therefore, not to describe the running-down of the Universe,
  but to understand its revival. When and how was exergy created, in
  particular the nuclear exergy, which is transformed into life-supporting
  light in our Sun? We have studied a model which should represent the
  nucleon gas of the early Universe quite well. We find that the main
  creation of nuclear exergy started around 10 s after the big bang,
  and most of the exergy was created during the first few minutes, 85%
  during the first hour, and that the process was essentially completed
  during the first 24 h. The final value of the exergy was 7.72 MeV per
  nucleon. The consumption of this exergy started much later and takes
  place in the stars over a time scale of hundreds and thousands of
  millions of years.

---------------------------------------------------------
Title: Outer atmospheres of cool stars. VIII. IUE observations
    and chromospheric models for the supergiant stars beta Draconis,
    epsilon Geminorum and alpha Orionis.
Authors: Basri, G. S.; Linsky, J. L.; Eriksson, K.
1981ApJ...251..162B    Altcode:
  A semiempirical modeling of stellar chromospheres is extended to
  late-type supergiants, where computations match high-resolution,
  absolute-flux profiles of the Ca II K and Mg II h and k lines. IUE
  UV spectra of Epsilon Gem and Alpha Ori show no evidence of emission
  lines formed at temperatures greater than 10,000 K, leading to the
  computation of chromospheric models extending to 10 to the -6th g/sq cm
  at temperatures that rise to 6500 K for the former star and 7000 K for
  the latter. By contrast, the C II-IV, Si IV, and He II and N V strong
  emission lines of Beta Dra lead to a tentative chromospheric model
  extension to 16,000 K at 0.012 dynes/sq cm. It is pointed out that
  the Ca II and Mg II line analyses presented, which assume hydrostatic
  equilibrium with only thermal and turbulent components to the pressure,
  imply nearly plane-parallel chromospheres even in the case of Alpha Ori.

---------------------------------------------------------
Title: A model of the outer atmosphere of beta Ceti.
Authors: Eriksson, K.; Simon, T.; Linsky, J. L.
1981BAAS...13..547E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: F Dwarfs
Authors: Eriksson, K.
1979iue..prop..367E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: The O I triplet lambda 7773 Å in late-type giant stars.
Authors: Eriksson, K.; Toft, S. C.
1979A&A....71..178E    Altcode:
  Observations of the 7773-A triplet of O I in about 20 G and K giants are
  presented which were performed with either an echelle photoelectric
  spectrophotometer or a high-dispersion spectrograph. Theoretical
  indices proportional to the difference in equivalent width between
  the lines in the line and continuum regions are obtained via non-LTE
  calculations of the 7773-A triplet lines, LTE computations of other
  lines in the two narrow bands observed, and use of the continuum slope
  in the framework of constant-flux line-blanketed model atmospheres
  with effective temperatures of 4000 to 5000 K, log g of 1.5 to 3.0,
  A/H in the range from -0.5 to 0.5, and a microturbulent velocity of
  1.7 km/s. The strengths of the 7773-A triplet lines and the 6300-A
  forbidden line of O I (computed in LTE) in different model atmospheres
  are examined, and it is found that the non-LTE effect for the 7773-A
  lines is to increase the equivalent widths by 10% to 30%. The behavior
  of the triplet lines in a model atmosphere with an effective temperature
  of 7600 K is briefly considered.

---------------------------------------------------------
Title: Observed transitions between the levels of the ground
    configuration in S I.
Authors: Eriksson, K. B. S.
1978ApJ...222..398E    Altcode:
  Accurate wavelengths of three transitions in the S I ground
  configuration are obtained, and the intensities are discussed in view
  of the theoretical transition probabilities. The level values are
  revised. The solar-line identifications are strengthened.

---------------------------------------------------------
Title: Soft gravitation radiation.
Authors: Alvegard, C.; Eriksson, K. -E.; Hogfors, C.
1978PhyS...17...95A    Altcode:
  The methods of soft photon radiation are applied to the linearized
  theory of gravitation in a radiation gauge similar to the radiation
  gauge in quantum electrodynamics. The time evolution of soft graviton
  emission following any scattering process is studied in detail. Results
  obtained by Weinberg in a different way are reproduced.

---------------------------------------------------------
Title: The oxygen triplet lambda 7773 Å in late-type giant stars.
Authors: Eriksson, K.
1978sss..meet..C15E    Altcode:
  No abstract at ADS

---------------------------------------------------------
Title: A grid of model atmospheres for metal-deficient giant
    stars. II.
Authors: Bell, R. A.; Eriksson, K.; Gustafsson, B.; Nordlund, A.
1976A&AS...23...37B    Altcode:
  Details are presented for a previously calculated grid of LTE model
  atmospheres for yellow and red giant stars. The grid covers the general
  range of effective temperatures from 3750 K to 6000 K, log g from 0.75
  to 3.0, and (A/H) from -3.0 to 0.0. For each model, numerical values
  are given for the optical depth, the Rosseland mean, the corresponding
  optical depth, the geometric depth and temperature, the electron
  pressure, gas pressure, radiative pressure, density, specific heat,
  and flux fraction. A model with typical solar parameters is included.

---------------------------------------------------------
Title: A grid of model atmospheres for metal-deficient giant stars. I.
Authors: Gustafsson, B.; Bell, R. A.; Eriksson, K.; Nordlund, A.
1975A&A....42..407G    Altcode: 2009A&A...500...67G
  A grid of flux-constant model atmospheres for stars with effective
  temperatures between 3750 and 6000 K, log g between 0.75 and 3.0, and
  (A/H) between -3.0 and 0.0 has been constructed. The line absorption
  is approximated by opacity distribution functions. Metal lines and
  molecular lines, including those from the infrared bands of CO and CN,
  are taken into account. The variation of the structure of the models
  with metal abundance and microturbulence parameter is found to be
  quite regular and not very drastic. The surface cooling produced
  by CO is important for all the models with a maximum temperature
  of 5000 K, while CN mainly causes a backwarming effect but is not
  very important for solar CNO abundances. The effects of convection,
  estimated by using the mixing-length approximation, are important only
  for the coldest models. The models compare very well with models from
  overlapping regions of other grids. A solar model consistent with the
  grid models is found to agree satisfactorily with empirical solar model
  atmospheres. The careful use of scaled solar models for stars with
  (A/H) approximately equal to zero is justified.

---------------------------------------------------------
Title: Forbidden transitions in S I.
Authors: Eriksson, K. B. S.
1973JOSA...63..632E    Altcode:
  No abstract at ADS