Towards a pure ZZ Ceti instability strip
Autor(a) principal: | |
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Data de Publicação: | 2007 |
Outros Autores: | , , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/98982 |
Resumo: | Context. We have observed again two stars inside the ZZ Ceti instability strip that were previously classified as not-observed-to-vary (NOV) by Mukadam et al. (2004) and found them to be low-amplitude variables. Some evidence points to a pure ZZ Ceti instability strip; other evidence contests it. Aims. The two stars previously classified as NOV have Sloan Digital Sky Survey (SDSS) spectroscopic effective temperatures that place them inside the ZZ Ceti instability strip, and they were “contaminating” the strip as constant stars, which could indicate that the instability strip was no longer a simple evolutionary stage. A pure instability strip indicates that pulsation is a normal phase which all DAs must go through. Methods. We used effective temperatures derived from SDSS optical spectra by comparing them with model atmospheres to look for pulsators through time-resolved photometry and stars previously classified as NOV. Results. Our new results indicate, but do not prove, a pure instability strip, because there are still other NOV stars that need to be observed again. Additionally, we have discovered five other ZZ Ceti stars based on their effective temperatures. |
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Castanheira, Bárbara GarciaKepler, Souza OliveiraCosta, Alex Fabiano Murillo daGiovannini Junior, OdilonRobinson, E.L.Winget, Donald EarlKleinman, Scot JamesNitta, AtsukoEisenstein, D.J.Koester, DetlevSantos, Marcio Gabriel dos2014-07-31T02:05:11Z20070004-6361http://hdl.handle.net/10183/98982000595607Context. We have observed again two stars inside the ZZ Ceti instability strip that were previously classified as not-observed-to-vary (NOV) by Mukadam et al. (2004) and found them to be low-amplitude variables. Some evidence points to a pure ZZ Ceti instability strip; other evidence contests it. Aims. The two stars previously classified as NOV have Sloan Digital Sky Survey (SDSS) spectroscopic effective temperatures that place them inside the ZZ Ceti instability strip, and they were “contaminating” the strip as constant stars, which could indicate that the instability strip was no longer a simple evolutionary stage. A pure instability strip indicates that pulsation is a normal phase which all DAs must go through. Methods. We used effective temperatures derived from SDSS optical spectra by comparing them with model atmospheres to look for pulsators through time-resolved photometry and stars previously classified as NOV. Results. Our new results indicate, but do not prove, a pure instability strip, because there are still other NOV stars that need to be observed again. Additionally, we have discovered five other ZZ Ceti stars based on their effective temperatures.application/pdfengAstronomy and astrophysics. Vol. 462, no. 3 (Feb. 2007), p. 989-993Anãs brancasEstrelasOscilacoesStars: white dwarfsStars: variables: generalStars: oscillationsTowards a pure ZZ Ceti instability stripEstrangeiroinfo: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:UFRGSORIGINAL000595607.pdf000595607.pdfTexto completo (inglês)application/pdf266991http://www.lume.ufrgs.br/bitstream/10183/98982/1/000595607.pdf101ff2a69f47cb49475f0499e62cdb9eMD51TEXT000595607.pdf.txt000595607.pdf.txtExtracted Texttext/plain26851http://www.lume.ufrgs.br/bitstream/10183/98982/2/000595607.pdf.txt9b8d93d8098d22d479ab666b5d26c401MD52THUMBNAIL000595607.pdf.jpg000595607.pdf.jpgGenerated Thumbnailimage/jpeg2074http://www.lume.ufrgs.br/bitstream/10183/98982/3/000595607.pdf.jpgea98a5ec98e1e4982d331341caa5a007MD5310183/989822018-10-22 08:18:39.844oai:www.lume.ufrgs.br:10183/98982Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2018-10-22T11:18:39Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Towards a pure ZZ Ceti instability strip |
title |
Towards a pure ZZ Ceti instability strip |
spellingShingle |
Towards a pure ZZ Ceti instability strip Castanheira, Bárbara Garcia Anãs brancas Estrelas Oscilacoes Stars: white dwarfs Stars: variables: general Stars: oscillations |
title_short |
Towards a pure ZZ Ceti instability strip |
title_full |
Towards a pure ZZ Ceti instability strip |
title_fullStr |
Towards a pure ZZ Ceti instability strip |
title_full_unstemmed |
Towards a pure ZZ Ceti instability strip |
title_sort |
Towards a pure ZZ Ceti instability strip |
author |
Castanheira, Bárbara Garcia |
author_facet |
Castanheira, Bárbara Garcia Kepler, Souza Oliveira Costa, Alex Fabiano Murillo da Giovannini Junior, Odilon Robinson, E.L. Winget, Donald Earl Kleinman, Scot James Nitta, Atsuko Eisenstein, D.J. Koester, Detlev Santos, Marcio Gabriel dos |
author_role |
author |
author2 |
Kepler, Souza Oliveira Costa, Alex Fabiano Murillo da Giovannini Junior, Odilon Robinson, E.L. Winget, Donald Earl Kleinman, Scot James Nitta, Atsuko Eisenstein, D.J. Koester, Detlev Santos, Marcio Gabriel dos |
author2_role |
author author author author author author author author author author |
dc.contributor.author.fl_str_mv |
Castanheira, Bárbara Garcia Kepler, Souza Oliveira Costa, Alex Fabiano Murillo da Giovannini Junior, Odilon Robinson, E.L. Winget, Donald Earl Kleinman, Scot James Nitta, Atsuko Eisenstein, D.J. Koester, Detlev Santos, Marcio Gabriel dos |
dc.subject.por.fl_str_mv |
Anãs brancas Estrelas Oscilacoes |
topic |
Anãs brancas Estrelas Oscilacoes Stars: white dwarfs Stars: variables: general Stars: oscillations |
dc.subject.eng.fl_str_mv |
Stars: white dwarfs Stars: variables: general Stars: oscillations |
description |
Context. We have observed again two stars inside the ZZ Ceti instability strip that were previously classified as not-observed-to-vary (NOV) by Mukadam et al. (2004) and found them to be low-amplitude variables. Some evidence points to a pure ZZ Ceti instability strip; other evidence contests it. Aims. The two stars previously classified as NOV have Sloan Digital Sky Survey (SDSS) spectroscopic effective temperatures that place them inside the ZZ Ceti instability strip, and they were “contaminating” the strip as constant stars, which could indicate that the instability strip was no longer a simple evolutionary stage. A pure instability strip indicates that pulsation is a normal phase which all DAs must go through. Methods. We used effective temperatures derived from SDSS optical spectra by comparing them with model atmospheres to look for pulsators through time-resolved photometry and stars previously classified as NOV. Results. Our new results indicate, but do not prove, a pure instability strip, because there are still other NOV stars that need to be observed again. Additionally, we have discovered five other ZZ Ceti stars based on their effective temperatures. |
publishDate |
2007 |
dc.date.issued.fl_str_mv |
2007 |
dc.date.accessioned.fl_str_mv |
2014-07-31T02:05:11Z |
dc.type.driver.fl_str_mv |
Estrangeiro info:eu-repo/semantics/article |
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info:eu-repo/semantics/publishedVersion |
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article |
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http://hdl.handle.net/10183/98982 |
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0004-6361 |
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000595607 |
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0004-6361 000595607 |
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http://hdl.handle.net/10183/98982 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Astronomy and astrophysics. Vol. 462, no. 3 (Feb. 2007), p. 989-993 |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
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