Measuring the evolution of the most stable optical clock G 117-B15A
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/108924 |
Resumo: | We report our measurement of the rate of change of period with time (˙P ) for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4σ measurement ˙Pobserved = (4.27± 0.80) x 10 15 s s-ˡ. Taking into account the proper-motion effect of ˙P proper = (7.0 ± 2.0) x 10 16 s s-ˡ,we obtain a rate of change of period with time of ˙P =(3.57 ± 0.82) ; 10 15 s s-ˡ. This value is consistent with the cooling rate in our white dwarf models only for cores of C or C/O. With the refinement of the models, the observed rate of period change can be used to accurately measure the ratio of C/O in the core of the white dwarf. |
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Kepler, Souza OliveiraCosta, Jose Eduardo da SilveiraCastanheira, Bárbara GarciaWinget, Donald EarlMullally, FergalNather, R. EdwardKilic, MukreminVon Hippel, Theodore A.Mukadam, Anjum ShaguftaSullivan, Denis J.2015-01-14T02:16:00Z20050004-637Xhttp://hdl.handle.net/10183/108924000537590We report our measurement of the rate of change of period with time (˙P ) for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4σ measurement ˙Pobserved = (4.27± 0.80) x 10 15 s s-ˡ. Taking into account the proper-motion effect of ˙P proper = (7.0 ± 2.0) x 10 16 s s-ˡ,we obtain a rate of change of period with time of ˙P =(3.57 ± 0.82) ; 10 15 s s-ˡ. This value is consistent with the cooling rate in our white dwarf models only for cores of C or C/O. With the refinement of the models, the observed rate of period change can be used to accurately measure the ratio of C/O in the core of the white dwarf.application/pdfengThe Astrophysical journal. Chicago. Vol. 634, no. 2, pt. 1 (Dec. 2005), p. 1311-1318Estrelas variaveisMovimento estelarPulsacoes estelaresAnãs brancasStars: evolutionStars: individual (G117-B15A)Stars: oscillationsMeasuring the evolution of the most stable optical clock G 117-B15AEstrangeiroinfo: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:UFRGSORIGINAL000537590.pdf000537590.pdfTexto completo (inglês)application/pdf217943http://www.lume.ufrgs.br/bitstream/10183/108924/1/000537590.pdf33c7e8476ed6298b219e030428921ae6MD51TEXT000537590.pdf.txt000537590.pdf.txtExtracted Texttext/plain44153http://www.lume.ufrgs.br/bitstream/10183/108924/2/000537590.pdf.txt723160938356a1a7bd7a588cc0aacc88MD52THUMBNAIL000537590.pdf.jpg000537590.pdf.jpgGenerated Thumbnailimage/jpeg1893http://www.lume.ufrgs.br/bitstream/10183/108924/3/000537590.pdf.jpg2feaa8b7e98b591bc9402f37944a0fadMD5310183/1089242023-08-16 03:30:40.72449oai:www.lume.ufrgs.br:10183/108924Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2023-08-16T06:30:40Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
Measuring the evolution of the most stable optical clock G 117-B15A |
title |
Measuring the evolution of the most stable optical clock G 117-B15A |
spellingShingle |
Measuring the evolution of the most stable optical clock G 117-B15A Kepler, Souza Oliveira Estrelas variaveis Movimento estelar Pulsacoes estelares Anãs brancas Stars: evolution Stars: individual (G117-B15A) Stars: oscillations |
title_short |
Measuring the evolution of the most stable optical clock G 117-B15A |
title_full |
Measuring the evolution of the most stable optical clock G 117-B15A |
title_fullStr |
Measuring the evolution of the most stable optical clock G 117-B15A |
title_full_unstemmed |
Measuring the evolution of the most stable optical clock G 117-B15A |
title_sort |
Measuring the evolution of the most stable optical clock G 117-B15A |
author |
Kepler, Souza Oliveira |
author_facet |
Kepler, Souza Oliveira Costa, Jose Eduardo da Silveira Castanheira, Bárbara Garcia Winget, Donald Earl Mullally, Fergal Nather, R. Edward Kilic, Mukremin Von Hippel, Theodore A. Mukadam, Anjum Shagufta Sullivan, Denis J. |
author_role |
author |
author2 |
Costa, Jose Eduardo da Silveira Castanheira, Bárbara Garcia Winget, Donald Earl Mullally, Fergal Nather, R. Edward Kilic, Mukremin Von Hippel, Theodore A. Mukadam, Anjum Shagufta Sullivan, Denis J. |
author2_role |
author author author author author author author author author |
dc.contributor.author.fl_str_mv |
Kepler, Souza Oliveira Costa, Jose Eduardo da Silveira Castanheira, Bárbara Garcia Winget, Donald Earl Mullally, Fergal Nather, R. Edward Kilic, Mukremin Von Hippel, Theodore A. Mukadam, Anjum Shagufta Sullivan, Denis J. |
dc.subject.por.fl_str_mv |
Estrelas variaveis Movimento estelar Pulsacoes estelares Anãs brancas |
topic |
Estrelas variaveis Movimento estelar Pulsacoes estelares Anãs brancas Stars: evolution Stars: individual (G117-B15A) Stars: oscillations |
dc.subject.eng.fl_str_mv |
Stars: evolution Stars: individual (G117-B15A) Stars: oscillations |
description |
We report our measurement of the rate of change of period with time (˙P ) for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have finally obtained a 4σ measurement ˙Pobserved = (4.27± 0.80) x 10 15 s s-ˡ. Taking into account the proper-motion effect of ˙P proper = (7.0 ± 2.0) x 10 16 s s-ˡ,we obtain a rate of change of period with time of ˙P =(3.57 ± 0.82) ; 10 15 s s-ˡ. This value is consistent with the cooling rate in our white dwarf models only for cores of C or C/O. With the refinement of the models, the observed rate of period change can be used to accurately measure the ratio of C/O in the core of the white dwarf. |
publishDate |
2005 |
dc.date.issued.fl_str_mv |
2005 |
dc.date.accessioned.fl_str_mv |
2015-01-14T02:16:00Z |
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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publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10183/108924 |
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0004-637X |
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000537590 |
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0004-637X 000537590 |
url |
http://hdl.handle.net/10183/108924 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
The Astrophysical journal. Chicago. Vol. 634, no. 2, pt. 1 (Dec. 2005), p. 1311-1318 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
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application/pdf |
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