Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations
International audience Recent spectropolarimetric studies of seven slowly pulsating B (SPB) and beta Cep stars have suggested that photospheric magnetic fields are more common in B-type pulsators than in the general population of B stars, suggesting a significant connection between magnetic and puls...
Published in: | The Astrophysical Journal |
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Main Authors: | , , , , , , , |
Other Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2012
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Online Access: | https://hal.science/hal-03729589 https://doi.org/10.1088/0004-637X/750/1/2 |
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Institut national des sciences de l'Univers: HAL-INSU |
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English |
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[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
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[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] Shultz, Matthew E. Wade, Gregg Grunhut, Jason Bagnulo, Stefano Landstreet, John D. Neiner, Coralie Alecian, Evelyne Hanes, David A. Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
topic_facet |
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
description |
International audience Recent spectropolarimetric studies of seven slowly pulsating B (SPB) and beta Cep stars have suggested that photospheric magnetic fields are more common in B-type pulsators than in the general population of B stars, suggesting a significant connection between magnetic and pulsational phenomena. We present an analysis of new and previously published spectropolarimetric observations of these stars. New Stokes V observations obtained with the high-resolution ESPaDOnS and Narval instruments confirm the presence of a magnetic field in one of the stars (epsilon Lup), but find no evidence of magnetism in five others. A re-analysis of the published longitudinal field measurements obtained with the low-resolution FORS1/2 spectropolarimeters finds that the measurements of all stars show more scatter from zero than can be attributed to Gaussian noise, suggesting the presence of a signal and/or systematic underestimation of error bars. Re-reduction and re-measurement of the FORS1/2 spectra from the ESO archive demonstrates that small changes in reduction procedure lead to substantial changes in the inferred longitudinal field, and substantially reduces the number of field detections at the 3sigma level. Furthermore, we find that the published periods are not unique solutions to the time series of either the original or the revised FORS1/2 data. We conclude that the reported field detections, proposed periods, and field geometry models for alpha Pyx, 15 CMa, 33 Eri, and V1449 Aql are artifacts of the data analysis and reduction procedures, and that magnetic fields at the reported strength are no more common in SPB/beta Cep stars than in the general population of B stars. |
author2 |
Royal Military College of Canada Armagh Observatory, College Hill Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) Etoile Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Department of Physics, Engineering Physics and Astronomy, Queen's University |
format |
Article in Journal/Newspaper |
author |
Shultz, Matthew E. Wade, Gregg Grunhut, Jason Bagnulo, Stefano Landstreet, John D. Neiner, Coralie Alecian, Evelyne Hanes, David A. |
author_facet |
Shultz, Matthew E. Wade, Gregg Grunhut, Jason Bagnulo, Stefano Landstreet, John D. Neiner, Coralie Alecian, Evelyne Hanes, David A. |
author_sort |
Shultz, Matthew E. |
title |
Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
title_short |
Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
title_full |
Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
title_fullStr |
Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
title_full_unstemmed |
Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations |
title_sort |
critical evaluation of magnetic field detections reported for pulsating b-type stars in light of espadons, narval, and reanalyzed fors1/2 observations |
publisher |
HAL CCSD |
publishDate |
2012 |
url |
https://hal.science/hal-03729589 https://doi.org/10.1088/0004-637X/750/1/2 |
genre |
narval narval |
genre_facet |
narval narval |
op_source |
ISSN: 0004-637X EISSN: 1538-4357 The Astrophysical Journal https://hal.science/hal-03729589 The Astrophysical Journal, 2012, 750, pp.2. ⟨10.1088/0004-637X/750/1/2⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/arxiv/1202.2384 info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-637X/750/1/2 hal-03729589 https://hal.science/hal-03729589 ARXIV: 1202.2384 BIBCODE: 2012ApJ.750.2S doi:10.1088/0004-637X/750/1/2 |
op_doi |
https://doi.org/10.1088/0004-637X/750/1/2 |
container_title |
The Astrophysical Journal |
container_volume |
750 |
container_issue |
1 |
container_start_page |
2 |
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1781707982518616064 |
spelling |
ftinsu:oai:HAL:hal-03729589v1 2023-11-05T03:45:27+01:00 Critical Evaluation of Magnetic Field Detections Reported for Pulsating B-type Stars in Light of ESPaDOnS, Narval, and Reanalyzed FORS1/2 Observations Shultz, Matthew E. Wade, Gregg Grunhut, Jason Bagnulo, Stefano Landstreet, John D. Neiner, Coralie Alecian, Evelyne Hanes, David A. Royal Military College of Canada Armagh Observatory, College Hill Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA) Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) Etoile Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité) Department of Physics, Engineering Physics and Astronomy, Queen's University 2012 https://hal.science/hal-03729589 https://doi.org/10.1088/0004-637X/750/1/2 en eng HAL CCSD American Astronomical Society info:eu-repo/semantics/altIdentifier/arxiv/1202.2384 info:eu-repo/semantics/altIdentifier/doi/10.1088/0004-637X/750/1/2 hal-03729589 https://hal.science/hal-03729589 ARXIV: 1202.2384 BIBCODE: 2012ApJ.750.2S doi:10.1088/0004-637X/750/1/2 ISSN: 0004-637X EISSN: 1538-4357 The Astrophysical Journal https://hal.science/hal-03729589 The Astrophysical Journal, 2012, 750, pp.2. ⟨10.1088/0004-637X/750/1/2⟩ [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] info:eu-repo/semantics/article Journal articles 2012 ftinsu https://doi.org/10.1088/0004-637X/750/1/2 2023-10-11T16:29:14Z International audience Recent spectropolarimetric studies of seven slowly pulsating B (SPB) and beta Cep stars have suggested that photospheric magnetic fields are more common in B-type pulsators than in the general population of B stars, suggesting a significant connection between magnetic and pulsational phenomena. We present an analysis of new and previously published spectropolarimetric observations of these stars. New Stokes V observations obtained with the high-resolution ESPaDOnS and Narval instruments confirm the presence of a magnetic field in one of the stars (epsilon Lup), but find no evidence of magnetism in five others. A re-analysis of the published longitudinal field measurements obtained with the low-resolution FORS1/2 spectropolarimeters finds that the measurements of all stars show more scatter from zero than can be attributed to Gaussian noise, suggesting the presence of a signal and/or systematic underestimation of error bars. Re-reduction and re-measurement of the FORS1/2 spectra from the ESO archive demonstrates that small changes in reduction procedure lead to substantial changes in the inferred longitudinal field, and substantially reduces the number of field detections at the 3sigma level. Furthermore, we find that the published periods are not unique solutions to the time series of either the original or the revised FORS1/2 data. We conclude that the reported field detections, proposed periods, and field geometry models for alpha Pyx, 15 CMa, 33 Eri, and V1449 Aql are artifacts of the data analysis and reduction procedures, and that magnetic fields at the reported strength are no more common in SPB/beta Cep stars than in the general population of B stars. Article in Journal/Newspaper narval narval Institut national des sciences de l'Univers: HAL-INSU The Astrophysical Journal 750 1 2 |