A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir)
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Outros Autores: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFRGS |
Texto Completo: | http://hdl.handle.net/10183/89981 |
Resumo: | We present results from a multisite (‘Whole Earth Telescope’) photometric campaign on PG 1336−018, the close eclipsing binary system containing a pulsating subdwarf B (sdB) star. The main part of the campaign (1999 April) resulted in ~172 h of observations, representing a coverage of about 47 per cent, and additional data were obtained outside the core campaign. Periodogram analysis shows that the light variations are dominated by three frequencies near 5757, 5585 and 5369 μHz (~174, 179 and 186s, respectively), although many frequencies are present, particularly in the range 5000–6000 μHz (~200–170 s). We identify, with some confidence, 28 frequencies down to a semi-amplitude of 0.0005 in fractional intensity (equivalent to about 0.5 mmag). It is clear that the pulsation frequencies of PG 1336−018 have changed substantially since the 1996 discovery observations were made, and that amplitude changes occur, at least in the dominant three frequencies, on relatively short time-scales (of the order of a day). On the assumption that the pulsating star is phase-locked in the binary system, we have searched for rotational splitting of frequencies near the orbital and half of the orbital period, but the results are confused by aliasing at those frequencies (due to the data gaps caused by the eclipses). A preliminary model qualitatively matches the distribution of frequencies in PG 1336−018, with some good individual correspondences, but cannot be considered adequate because geometric cancellation should hide some of the modes which are apparently detected. Analysis of the pulsations during eclipse recovers three of the strongest modes, but the limited eclipse data – which can, at best, be only about 9 per cent of the total – do not allow mode identification at this stage. Simulations indicate that an overall coverage of about 80 per cent would be required for this to be viable. An attempt was made to determine phase shifts in the pulsation frequencies as a way of directly measuring the size of the binary orbit, but the uncertainties in the method are comparable to the light travel time across the orbit (probably less than a second). |
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Kilkenny, DaveReed, M. D.O'Donoghue, DarraghKawaler, Steven D.Mukadam, Anjum ShaguftaKleinman, Scot JamesNitta, AtsukoMetcalfe, Travis S.Provencal, Judith L.Watson, Todd K.Sullivan, Denis J.Sullivan, TerryShobbrook, Robert R.Jiang, XiaojunJoshi, SantoshAshoka, B.N.Seetha, S.Leibowitz, Elia M.Ibbetson, Peter A.Mendelson, HaimMeistas, Edmundas G.Kalytis, RomualdasAlisauskas, DariusMartinez, PeterVan Wyk, FrancoisStobie, Robert S.Marang, FredZola, StaszekKrzesinski, JerzyOgloza, WaldemarMoskalik, PawelSilvotti, RobertoPiccioni, AdalbertoVauclair, GérardDolez, NoëlChevreton, MichelDreizler, StefanSchuh, Sonja L.Deetjen, Jochen L.Solheim, Jan-EricGonzalez Perez, Jose MiguelUlla, AnaOstensen, RoyManteiga, MiniaSuarez, OlgaBurleigh, MattKepler, Souza OliveiraKanaan Neto, Antonio NemerGiovannini Junior, Odilon2014-03-29T01:51:44Z20030035-8711http://hdl.handle.net/10183/89981000393691We present results from a multisite (‘Whole Earth Telescope’) photometric campaign on PG 1336−018, the close eclipsing binary system containing a pulsating subdwarf B (sdB) star. The main part of the campaign (1999 April) resulted in ~172 h of observations, representing a coverage of about 47 per cent, and additional data were obtained outside the core campaign. Periodogram analysis shows that the light variations are dominated by three frequencies near 5757, 5585 and 5369 μHz (~174, 179 and 186s, respectively), although many frequencies are present, particularly in the range 5000–6000 μHz (~200–170 s). We identify, with some confidence, 28 frequencies down to a semi-amplitude of 0.0005 in fractional intensity (equivalent to about 0.5 mmag). It is clear that the pulsation frequencies of PG 1336−018 have changed substantially since the 1996 discovery observations were made, and that amplitude changes occur, at least in the dominant three frequencies, on relatively short time-scales (of the order of a day). On the assumption that the pulsating star is phase-locked in the binary system, we have searched for rotational splitting of frequencies near the orbital and half of the orbital period, but the results are confused by aliasing at those frequencies (due to the data gaps caused by the eclipses). A preliminary model qualitatively matches the distribution of frequencies in PG 1336−018, with some good individual correspondences, but cannot be considered adequate because geometric cancellation should hide some of the modes which are apparently detected. Analysis of the pulsations during eclipse recovers three of the strongest modes, but the limited eclipse data – which can, at best, be only about 9 per cent of the total – do not allow mode identification at this stage. Simulations indicate that an overall coverage of about 80 per cent would be required for this to be viable. An attempt was made to determine phase shifts in the pulsation frequencies as a way of directly measuring the size of the binary orbit, but the uncertainties in the method are comparable to the light travel time across the orbit (probably less than a second).application/pdfengMonthly notices of the Royal Astronomical Society. Oxford. Vol. 345, no. 3 (Nov. 2003), p. 834-846EstrelasFotometria estelarPulsacoes estelaresFotometria astronômicaStars: individual: PG 1336−018Stars: oscillationsStars: variables: otherA Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir)Estrangeiroinfo: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:UFRGSORIGINAL000393691.pdf000393691.pdfTexto completo (inglês)application/pdf611583http://www.lume.ufrgs.br/bitstream/10183/89981/1/000393691.pdf94c0e05ad005b98878592be60048a5c1MD51TEXT000393691.pdf.txt000393691.pdf.txtExtracted Texttext/plain66147http://www.lume.ufrgs.br/bitstream/10183/89981/2/000393691.pdf.txtf4b4b6a02293c65601fc2c91dfd2207aMD52THUMBNAIL000393691.pdf.jpg000393691.pdf.jpgGenerated Thumbnailimage/jpeg1926http://www.lume.ufrgs.br/bitstream/10183/89981/3/000393691.pdf.jpg8e112de58a7657ea4bfa81f13564afd8MD5310183/899812022-02-22 05:17:28.244658oai:www.lume.ufrgs.br:10183/89981Repositório de PublicaçõesPUBhttps://lume.ufrgs.br/oai/requestopendoar:2022-02-22T08:17:28Repositório Institucional da UFRGS - Universidade Federal do Rio Grande do Sul (UFRGS)false |
dc.title.pt_BR.fl_str_mv |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
title |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
spellingShingle |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) Kilkenny, Dave Estrelas Fotometria estelar Pulsacoes estelares Fotometria astronômica Stars: individual: PG 1336−018 Stars: oscillations Stars: variables: other |
title_short |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
title_full |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
title_fullStr |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
title_full_unstemmed |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
title_sort |
A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |
author |
Kilkenny, Dave |
author_facet |
Kilkenny, Dave Reed, M. D. O'Donoghue, Darragh Kawaler, Steven D. Mukadam, Anjum Shagufta Kleinman, Scot James Nitta, Atsuko Metcalfe, Travis S. Provencal, Judith L. Watson, Todd K. Sullivan, Denis J. Sullivan, Terry Shobbrook, Robert R. Jiang, Xiaojun Joshi, Santosh Ashoka, B.N. Seetha, S. Leibowitz, Elia M. Ibbetson, Peter A. Mendelson, Haim Meistas, Edmundas G. Kalytis, Romualdas Alisauskas, Darius Martinez, Peter Van Wyk, Francois Stobie, Robert S. Marang, Fred Zola, Staszek Krzesinski, Jerzy Ogloza, Waldemar Moskalik, Pawel Silvotti, Roberto Piccioni, Adalberto Vauclair, Gérard Dolez, Noël Chevreton, Michel Dreizler, Stefan Schuh, Sonja L. Deetjen, Jochen L. Solheim, Jan-Eric Gonzalez Perez, Jose Miguel Ulla, Ana Ostensen, Roy Manteiga, Minia Suarez, Olga Burleigh, Matt Kepler, Souza Oliveira Kanaan Neto, Antonio Nemer Giovannini Junior, Odilon |
author_role |
author |
author2 |
Reed, M. D. O'Donoghue, Darragh Kawaler, Steven D. Mukadam, Anjum Shagufta Kleinman, Scot James Nitta, Atsuko Metcalfe, Travis S. Provencal, Judith L. Watson, Todd K. Sullivan, Denis J. Sullivan, Terry Shobbrook, Robert R. Jiang, Xiaojun Joshi, Santosh Ashoka, B.N. Seetha, S. Leibowitz, Elia M. Ibbetson, Peter A. Mendelson, Haim Meistas, Edmundas G. Kalytis, Romualdas Alisauskas, Darius Martinez, Peter Van Wyk, Francois Stobie, Robert S. Marang, Fred Zola, Staszek Krzesinski, Jerzy Ogloza, Waldemar Moskalik, Pawel Silvotti, Roberto Piccioni, Adalberto Vauclair, Gérard Dolez, Noël Chevreton, Michel Dreizler, Stefan Schuh, Sonja L. Deetjen, Jochen L. Solheim, Jan-Eric Gonzalez Perez, Jose Miguel Ulla, Ana Ostensen, Roy Manteiga, Minia Suarez, Olga Burleigh, Matt Kepler, Souza Oliveira Kanaan Neto, Antonio Nemer Giovannini Junior, Odilon |
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 |
dc.contributor.author.fl_str_mv |
Kilkenny, Dave Reed, M. D. O'Donoghue, Darragh Kawaler, Steven D. Mukadam, Anjum Shagufta Kleinman, Scot James Nitta, Atsuko Metcalfe, Travis S. Provencal, Judith L. Watson, Todd K. Sullivan, Denis J. Sullivan, Terry Shobbrook, Robert R. Jiang, Xiaojun Joshi, Santosh Ashoka, B.N. Seetha, S. Leibowitz, Elia M. Ibbetson, Peter A. Mendelson, Haim Meistas, Edmundas G. Kalytis, Romualdas Alisauskas, Darius Martinez, Peter Van Wyk, Francois Stobie, Robert S. Marang, Fred Zola, Staszek Krzesinski, Jerzy Ogloza, Waldemar Moskalik, Pawel Silvotti, Roberto Piccioni, Adalberto Vauclair, Gérard Dolez, Noël Chevreton, Michel Dreizler, Stefan Schuh, Sonja L. Deetjen, Jochen L. Solheim, Jan-Eric Gonzalez Perez, Jose Miguel Ulla, Ana Ostensen, Roy Manteiga, Minia Suarez, Olga Burleigh, Matt Kepler, Souza Oliveira Kanaan Neto, Antonio Nemer Giovannini Junior, Odilon |
dc.subject.por.fl_str_mv |
Estrelas Fotometria estelar Pulsacoes estelares Fotometria astronômica |
topic |
Estrelas Fotometria estelar Pulsacoes estelares Fotometria astronômica Stars: individual: PG 1336−018 Stars: oscillations Stars: variables: other |
dc.subject.eng.fl_str_mv |
Stars: individual: PG 1336−018 Stars: oscillations Stars: variables: other |
description |
We present results from a multisite (‘Whole Earth Telescope’) photometric campaign on PG 1336−018, the close eclipsing binary system containing a pulsating subdwarf B (sdB) star. The main part of the campaign (1999 April) resulted in ~172 h of observations, representing a coverage of about 47 per cent, and additional data were obtained outside the core campaign. Periodogram analysis shows that the light variations are dominated by three frequencies near 5757, 5585 and 5369 μHz (~174, 179 and 186s, respectively), although many frequencies are present, particularly in the range 5000–6000 μHz (~200–170 s). We identify, with some confidence, 28 frequencies down to a semi-amplitude of 0.0005 in fractional intensity (equivalent to about 0.5 mmag). It is clear that the pulsation frequencies of PG 1336−018 have changed substantially since the 1996 discovery observations were made, and that amplitude changes occur, at least in the dominant three frequencies, on relatively short time-scales (of the order of a day). On the assumption that the pulsating star is phase-locked in the binary system, we have searched for rotational splitting of frequencies near the orbital and half of the orbital period, but the results are confused by aliasing at those frequencies (due to the data gaps caused by the eclipses). A preliminary model qualitatively matches the distribution of frequencies in PG 1336−018, with some good individual correspondences, but cannot be considered adequate because geometric cancellation should hide some of the modes which are apparently detected. Analysis of the pulsations during eclipse recovers three of the strongest modes, but the limited eclipse data – which can, at best, be only about 9 per cent of the total – do not allow mode identification at this stage. Simulations indicate that an overall coverage of about 80 per cent would be required for this to be viable. An attempt was made to determine phase shifts in the pulsation frequencies as a way of directly measuring the size of the binary orbit, but the uncertainties in the method are comparable to the light travel time across the orbit (probably less than a second). |
publishDate |
2003 |
dc.date.issued.fl_str_mv |
2003 |
dc.date.accessioned.fl_str_mv |
2014-03-29T01:51:44Z |
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Estrangeiro info:eu-repo/semantics/article |
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publishedVersion |
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http://hdl.handle.net/10183/89981 |
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0035-8711 |
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000393691 |
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http://hdl.handle.net/10183/89981 |
dc.language.iso.fl_str_mv |
eng |
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eng |
dc.relation.ispartof.pt_BR.fl_str_mv |
Monthly notices of the Royal Astronomical Society. Oxford. Vol. 345, no. 3 (Nov. 2003), p. 834-846 |
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