2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV

Detalhes bibliográficos
Autor(a) principal: Provencal, Judith L.
Data de Publicação: 2009
Outros Autores: Montgomery, Michael Houston, Kanaan Neto, Antonio Nemer, Shipman, Harry L., Childers, D., Baran, Andrzej, Kepler, Souza Oliveira, Reed, M. D., Zhou, Ai-Ying, Eggen, J., Watson, Todd K., Winget, Donald Earl, Thompson, S. E., Riaz, B., Nitta, Atsuko, Kleinman, Scot James, Crowe, Richard A., Slivkoff, Jay, Sherard, P., Purves, Norman G., Binder, Philippe M., Knight, R., Kim, Seung-Lee, Chen, Wen-Ping, Yang, M., Lin, Hung-Chin, Lin, Chien-Cheng, Chen, C.-W., Jiang, Xiaojun, Sergeev, A., Mkrtichian, David, Andreev, M., Janulis, Rimvydas, Siwak, Michal, Zola, Staszek, Koziel-Wierzbowska, Dorota, Stachowski, G., Paparo, Margit, Bognár, Zsófia, Handler, Gerald, Lorenz, Denise, Steininger, Bruno, Beck, Paul, Nagel, Thorsten, Kusterer, D., Hoffman, A., Reiff, E., Kowalski, R., Vauclair, Gérard, Charpinet, Stéphane, Chevreton, Michel, Solheim, Jan-Eric, Pakstiene, Erika, Fraga, Luciano, Dalessio, J.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UFRGS
Texto Completo: http://hdl.handle.net/10183/108971
Resumo: We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 μHz, with the dominant peak at 1234 μHz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l =l modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k multiplets is highly suspect. The k = 9 and 8 modes typically do show triplet structure more consistent with theoretical expectations. The frequencies and amplitudes exhibit some variability, but much less than the high-k modes. Analysis of the k = 9 and 8 multiplet splittings from 1990 to 2008 reveal a long-term change in multiplet splittings coinciding with the 1996 sforzando event, where GD358 dramatically altered its pulsation characteristics on a timescale of hours. We explore potential implications, including the possible connections between convection and/or magnetic fields and pulsations.We suggest future investigations, including theoretical investigations of the relationship between magnetic fields, pulsation, growth rates, and convection.
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spelling Provencal, Judith L.Montgomery, Michael HoustonKanaan Neto, Antonio NemerShipman, Harry L.Childers, D.Baran, AndrzejKepler, Souza OliveiraReed, M. D.Zhou, Ai-YingEggen, J.Watson, Todd K.Winget, Donald EarlThompson, S. E.Riaz, B.Nitta, AtsukoKleinman, Scot JamesCrowe, Richard A.Slivkoff, JaySherard, P.Purves, Norman G.Binder, Philippe M.Knight, R.Kim, Seung-LeeChen, Wen-PingYang, M.Lin, Hung-ChinLin, Chien-ChengChen, C.-W.Jiang, XiaojunSergeev, A.Mkrtichian, DavidAndreev, M.Janulis, RimvydasSiwak, MichalZola, StaszekKoziel-Wierzbowska, DorotaStachowski, G.Paparo, MargitBognár, ZsófiaHandler, GeraldLorenz, DeniseSteininger, BrunoBeck, PaulNagel, ThorstenKusterer, D.Hoffman, A.Reiff, E.Kowalski, R.Vauclair, GérardCharpinet, StéphaneChevreton, MichelSolheim, Jan-EricPakstiene, ErikaFraga, LucianoDalessio, J.2015-01-15T02:15:09Z20090004-637Xhttp://hdl.handle.net/10183/108971000766225We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 μHz, with the dominant peak at 1234 μHz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l =l modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k multiplets is highly suspect. The k = 9 and 8 modes typically do show triplet structure more consistent with theoretical expectations. The frequencies and amplitudes exhibit some variability, but much less than the high-k modes. Analysis of the k = 9 and 8 multiplet splittings from 1990 to 2008 reveal a long-term change in multiplet splittings coinciding with the 1996 sforzando event, where GD358 dramatically altered its pulsation characteristics on a timescale of hours. We explore potential implications, including the possible connections between convection and/or magnetic fields and pulsations.We suggest future investigations, including theoretical investigations of the relationship between magnetic fields, pulsation, growth rates, and convection.application/pdfengThe astrophysical journal. Bristol. Vol. 693, no. 1 (Mar. 2009), p. 564-585Evolucao estelarDinâmica de fluidos astrofísicosPulsacoes estelaresMagnetismo estelarRadiação estelarEspectros estelaresEstrutura estelarEstrelas variaveisAnãs brancasStars: evolutionStars: individual (GD358)Stars: oscillationsWhite dwarfs2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBVEstrangeiroinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFRGSinstname:Universidade Federal do Rio Grande do Sul (UFRGS)instacron:UFRGSORIGINAL000766225.pdf000766225.pdfTexto completo (inglês)application/pdf3178852http://www.lume.ufrgs.br/bitstream/10183/108971/1/000766225.pdf489a4089753a31004ad75dd8efbc03d8MD51TEXT000766225.pdf.txt000766225.pdf.txtExtracted Texttext/plain94202http://www.lume.ufrgs.br/bitstream/10183/108971/2/000766225.pdf.txt421e17ec94ead9482ad8334daaddcceaMD52THUMBNAIL000766225.pdf.jpg000766225.pdf.jpgGenerated Thumbnailimage/jpeg2063http://www.lume.ufrgs.br/bitstream/10183/108971/3/000766225.pdf.jpg0c094e38332038b69ff9be143c16642fMD5310183/1089712018-10-23 08:40:20.63oai:www.lume.ufrgs.br:10183/108971Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-23T11:40:20Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false
dc.title.pt_BR.fl_str_mv 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
title 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
spellingShingle 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
Provencal, Judith L.
Evolucao estelar
Dinâmica de fluidos astrofísicos
Pulsacoes estelares
Magnetismo estelar
Radiação estelar
Espectros estelares
Estrutura estelar
Estrelas variaveis
Anãs brancas
Stars: evolution
Stars: individual (GD358)
Stars: oscillations
White dwarfs
title_short 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
title_full 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
title_fullStr 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
title_full_unstemmed 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
title_sort 2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
author Provencal, Judith L.
author_facet Provencal, Judith L.
Montgomery, Michael Houston
Kanaan Neto, Antonio Nemer
Shipman, Harry L.
Childers, D.
Baran, Andrzej
Kepler, Souza Oliveira
Reed, M. D.
Zhou, Ai-Ying
Eggen, J.
Watson, Todd K.
Winget, Donald Earl
Thompson, S. E.
Riaz, B.
Nitta, Atsuko
Kleinman, Scot James
Crowe, Richard A.
Slivkoff, Jay
Sherard, P.
Purves, Norman G.
Binder, Philippe M.
Knight, R.
Kim, Seung-Lee
Chen, Wen-Ping
Yang, M.
Lin, Hung-Chin
Lin, Chien-Cheng
Chen, C.-W.
Jiang, Xiaojun
Sergeev, A.
Mkrtichian, David
Andreev, M.
Janulis, Rimvydas
Siwak, Michal
Zola, Staszek
Koziel-Wierzbowska, Dorota
Stachowski, G.
Paparo, Margit
Bognár, Zsófia
Handler, Gerald
Lorenz, Denise
Steininger, Bruno
Beck, Paul
Nagel, Thorsten
Kusterer, D.
Hoffman, A.
Reiff, E.
Kowalski, R.
Vauclair, Gérard
Charpinet, Stéphane
Chevreton, Michel
Solheim, Jan-Eric
Pakstiene, Erika
Fraga, Luciano
Dalessio, J.
author_role author
author2 Montgomery, Michael Houston
Kanaan Neto, Antonio Nemer
Shipman, Harry L.
Childers, D.
Baran, Andrzej
Kepler, Souza Oliveira
Reed, M. D.
Zhou, Ai-Ying
Eggen, J.
Watson, Todd K.
Winget, Donald Earl
Thompson, S. E.
Riaz, B.
Nitta, Atsuko
Kleinman, Scot James
Crowe, Richard A.
Slivkoff, Jay
Sherard, P.
Purves, Norman G.
Binder, Philippe M.
Knight, R.
Kim, Seung-Lee
Chen, Wen-Ping
Yang, M.
Lin, Hung-Chin
Lin, Chien-Cheng
Chen, C.-W.
Jiang, Xiaojun
Sergeev, A.
Mkrtichian, David
Andreev, M.
Janulis, Rimvydas
Siwak, Michal
Zola, Staszek
Koziel-Wierzbowska, Dorota
Stachowski, G.
Paparo, Margit
Bognár, Zsófia
Handler, Gerald
Lorenz, Denise
Steininger, Bruno
Beck, Paul
Nagel, Thorsten
Kusterer, D.
Hoffman, A.
Reiff, E.
Kowalski, R.
Vauclair, Gérard
Charpinet, Stéphane
Chevreton, Michel
Solheim, Jan-Eric
Pakstiene, Erika
Fraga, Luciano
Dalessio, J.
author2_role author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
author
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dc.contributor.author.fl_str_mv Provencal, Judith L.
Montgomery, Michael Houston
Kanaan Neto, Antonio Nemer
Shipman, Harry L.
Childers, D.
Baran, Andrzej
Kepler, Souza Oliveira
Reed, M. D.
Zhou, Ai-Ying
Eggen, J.
Watson, Todd K.
Winget, Donald Earl
Thompson, S. E.
Riaz, B.
Nitta, Atsuko
Kleinman, Scot James
Crowe, Richard A.
Slivkoff, Jay
Sherard, P.
Purves, Norman G.
Binder, Philippe M.
Knight, R.
Kim, Seung-Lee
Chen, Wen-Ping
Yang, M.
Lin, Hung-Chin
Lin, Chien-Cheng
Chen, C.-W.
Jiang, Xiaojun
Sergeev, A.
Mkrtichian, David
Andreev, M.
Janulis, Rimvydas
Siwak, Michal
Zola, Staszek
Koziel-Wierzbowska, Dorota
Stachowski, G.
Paparo, Margit
Bognár, Zsófia
Handler, Gerald
Lorenz, Denise
Steininger, Bruno
Beck, Paul
Nagel, Thorsten
Kusterer, D.
Hoffman, A.
Reiff, E.
Kowalski, R.
Vauclair, Gérard
Charpinet, Stéphane
Chevreton, Michel
Solheim, Jan-Eric
Pakstiene, Erika
Fraga, Luciano
Dalessio, J.
dc.subject.por.fl_str_mv Evolucao estelar
Dinâmica de fluidos astrofísicos
Pulsacoes estelares
Magnetismo estelar
Radiação estelar
Espectros estelares
Estrutura estelar
Estrelas variaveis
Anãs brancas
topic Evolucao estelar
Dinâmica de fluidos astrofísicos
Pulsacoes estelares
Magnetismo estelar
Radiação estelar
Espectros estelares
Estrutura estelar
Estrelas variaveis
Anãs brancas
Stars: evolution
Stars: individual (GD358)
Stars: oscillations
White dwarfs
dc.subject.eng.fl_str_mv Stars: evolution
Stars: individual (GD358)
Stars: oscillations
White dwarfs
description We report on the analysis of 436.1 hr of nearly continuous high-speed photometry on the pulsating DB white dwarf GD358 acquired with the Whole Earth Telescope (WET) during the 2006 international observing run, designated XCOV25. The Fourier transform (FT) of the light curve contains power between 1000 and 4000 μHz, with the dominant peak at 1234 μHz. We find 27 independent frequencies distributed in 10 modes, as well as numerous combination frequencies. Our discussion focuses on a new asteroseismological analysis of GD358, incorporating the 2006 data set and drawing on 24 years of archival observations. Our results reveal that, while the general frequency locations of the identified modes are consistent throughout the years, the multiplet structure is complex and cannot be interpreted simply as l =l modes in the limit of slow rotation. The high-k multiplets exhibit significant variability in structure, amplitude and frequency. Any identification of the m components for the high-k multiplets is highly suspect. The k = 9 and 8 modes typically do show triplet structure more consistent with theoretical expectations. The frequencies and amplitudes exhibit some variability, but much less than the high-k modes. Analysis of the k = 9 and 8 multiplet splittings from 1990 to 2008 reveal a long-term change in multiplet splittings coinciding with the 1996 sforzando event, where GD358 dramatically altered its pulsation characteristics on a timescale of hours. We explore potential implications, including the possible connections between convection and/or magnetic fields and pulsations.We suggest future investigations, including theoretical investigations of the relationship between magnetic fields, pulsation, growth rates, and convection.
publishDate 2009
dc.date.issued.fl_str_mv 2009
dc.date.accessioned.fl_str_mv 2015-01-15T02:15:09Z
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dc.identifier.uri.fl_str_mv http://hdl.handle.net/10183/108971
dc.identifier.issn.pt_BR.fl_str_mv 0004-637X
dc.identifier.nrb.pt_BR.fl_str_mv 000766225
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dc.relation.ispartof.pt_BR.fl_str_mv The astrophysical journal. Bristol. Vol. 693, no. 1 (Mar. 2009), p. 564-585
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