Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere
In this paper, we report 23 magnetic field measurements of the B3IV star HD 23478: 12 obtained from high-resolution Stokes V spectra using the ESPaDOnS (Canada–France–Hawaii Telescope) and Narval (Télescope Bernard Lyot) spectropolarimeters, and 11 from medium-resolution Stokes V spectra obtained wi...
Published in: | Monthly Notices of the Royal Astronomical Society |
---|---|
Main Authors: | , , , , , , , , , , , , , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2015
|
Subjects: | |
Online Access: | http://mnras.oxfordjournals.org/cgi/content/short/451/2/1928 https://doi.org/10.1093/mnras/stv1051 |
id |
fthighwire:oai:open-archive.highwire.org:mnras:451/2/1928 |
---|---|
record_format |
openpolar |
spelling |
fthighwire:oai:open-archive.highwire.org:mnras:451/2/1928 2023-05-15T18:50:48+02:00 Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere Sikora, J. Wade, G. A. Bohlender, D. A. Neiner, C. Oksala, M. E. Shultz, M. Cohen, D. H. ud-Doula, A. Grunhut, J. Monin, D. Owocki, S. Petit, V. Rivinus, T. Townsend, R. H. D. 2015-06-09 17:40:36.0 text/html http://mnras.oxfordjournals.org/cgi/content/short/451/2/1928 https://doi.org/10.1093/mnras/stv1051 en eng Oxford University Press http://mnras.oxfordjournals.org/cgi/content/short/451/2/1928 http://dx.doi.org/10.1093/mnras/stv1051 Copyright (C) 2015, Oxford University Press Article TEXT 2015 fthighwire https://doi.org/10.1093/mnras/stv1051 2016-11-16T17:07:01Z In this paper, we report 23 magnetic field measurements of the B3IV star HD 23478: 12 obtained from high-resolution Stokes V spectra using the ESPaDOnS (Canada–France–Hawaii Telescope) and Narval (Télescope Bernard Lyot) spectropolarimeters, and 11 from medium-resolution Stokes V spectra obtained with the DimaPol spectropolarimeter (Dominion Astronomical Observatory). HD 23478 was one of two rapidly rotating stars identified as potential ‘centrifugal magnetosphere’ hosts based on IR observations from the Apache Point Observatory Galactic Evolution Experiment survey. We derive basic physical properties of this star including its mass (<f>$M=6.1^{+0.8}_{-0.7}\,\mathrm{M}_{\odot }$</f>), effective temperature ( T eff = 20 ± 2 kK), radius (<f>$R=2.7^{+1.6}_{-0.9}\,\mathrm{R}_{\odot }$</f>), and age (<f>$\tau _{\rm age}=3^{+37}_{-1}\,{\rm Myr}$</f>). We repeatedly detect weakly variable Zeeman signatures in metal, He, and H lines in all our observations corresponding to a longitudinal magnetic field of 〈 B z 〉 ≈ −2.0 kG. The rotational period is inferred from Hipparcos photometry ( P rot = 1.0498(4) d). Under the assumption of the Oblique Rotator Model, our observations yield a surface dipole magnetic field of strength B d ≥ 9.5 kG that is approximately aligned with the stellar rotation axis. We confirm the presence of strong and broad Hα emission and gauge the volume of this star's centrifugal magnetosphere to be consistent with those of other Hα emitting centrifugal magnetosphere stars based on the large inferred Alfvén to Kepler radius ratio. Text narval narval HighWire Press (Stanford University) Canada Monthly Notices of the Royal Astronomical Society 451 2 1928 1938 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Article |
spellingShingle |
Article Sikora, J. Wade, G. A. Bohlender, D. A. Neiner, C. Oksala, M. E. Shultz, M. Cohen, D. H. ud-Doula, A. Grunhut, J. Monin, D. Owocki, S. Petit, V. Rivinus, T. Townsend, R. H. D. Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
topic_facet |
Article |
description |
In this paper, we report 23 magnetic field measurements of the B3IV star HD 23478: 12 obtained from high-resolution Stokes V spectra using the ESPaDOnS (Canada–France–Hawaii Telescope) and Narval (Télescope Bernard Lyot) spectropolarimeters, and 11 from medium-resolution Stokes V spectra obtained with the DimaPol spectropolarimeter (Dominion Astronomical Observatory). HD 23478 was one of two rapidly rotating stars identified as potential ‘centrifugal magnetosphere’ hosts based on IR observations from the Apache Point Observatory Galactic Evolution Experiment survey. We derive basic physical properties of this star including its mass (<f>$M=6.1^{+0.8}_{-0.7}\,\mathrm{M}_{\odot }$</f>), effective temperature ( T eff = 20 ± 2 kK), radius (<f>$R=2.7^{+1.6}_{-0.9}\,\mathrm{R}_{\odot }$</f>), and age (<f>$\tau _{\rm age}=3^{+37}_{-1}\,{\rm Myr}$</f>). We repeatedly detect weakly variable Zeeman signatures in metal, He, and H lines in all our observations corresponding to a longitudinal magnetic field of 〈 B z 〉 ≈ −2.0 kG. The rotational period is inferred from Hipparcos photometry ( P rot = 1.0498(4) d). Under the assumption of the Oblique Rotator Model, our observations yield a surface dipole magnetic field of strength B d ≥ 9.5 kG that is approximately aligned with the stellar rotation axis. We confirm the presence of strong and broad Hα emission and gauge the volume of this star's centrifugal magnetosphere to be consistent with those of other Hα emitting centrifugal magnetosphere stars based on the large inferred Alfvén to Kepler radius ratio. |
format |
Text |
author |
Sikora, J. Wade, G. A. Bohlender, D. A. Neiner, C. Oksala, M. E. Shultz, M. Cohen, D. H. ud-Doula, A. Grunhut, J. Monin, D. Owocki, S. Petit, V. Rivinus, T. Townsend, R. H. D. |
author_facet |
Sikora, J. Wade, G. A. Bohlender, D. A. Neiner, C. Oksala, M. E. Shultz, M. Cohen, D. H. ud-Doula, A. Grunhut, J. Monin, D. Owocki, S. Petit, V. Rivinus, T. Townsend, R. H. D. |
author_sort |
Sikora, J. |
title |
Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
title_short |
Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
title_full |
Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
title_fullStr |
Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
title_full_unstemmed |
Confirming HD 23478 as a new magnetic B star hosting an H{alpha}-bright centrifugal magnetosphere |
title_sort |
confirming hd 23478 as a new magnetic b star hosting an h{alpha}-bright centrifugal magnetosphere |
publisher |
Oxford University Press |
publishDate |
2015 |
url |
http://mnras.oxfordjournals.org/cgi/content/short/451/2/1928 https://doi.org/10.1093/mnras/stv1051 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
narval narval |
genre_facet |
narval narval |
op_relation |
http://mnras.oxfordjournals.org/cgi/content/short/451/2/1928 http://dx.doi.org/10.1093/mnras/stv1051 |
op_rights |
Copyright (C) 2015, Oxford University Press |
op_doi |
https://doi.org/10.1093/mnras/stv1051 |
container_title |
Monthly Notices of the Royal Astronomical Society |
container_volume |
451 |
container_issue |
2 |
container_start_page |
1928 |
op_container_end_page |
1938 |
_version_ |
1766244552106049536 |