2006 Whole Earth Telescope observations of GD358 : a new look at the prototype DBV
Autor(a) principal: | |
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Data de Publicação: | 2009 |
Outros Autores: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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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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 author author author author author author author author author author author author author author author author author author author author author |
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 |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/108971 |
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0004-637X |
dc.identifier.nrb.pt_BR.fl_str_mv |
000766225 |
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0004-637X 000766225 |
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http://hdl.handle.net/10183/108971 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
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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info:eu-repo/semantics/openAccess |
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openAccess |
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